A Strategic Assessment of Crown 

Fire Hazard in Montana: Potential 

Effectiveness and Costs of Hazard 

Reduction Treatments

Carl E. Fiedler, Charles E. Keegan III, Christopher W. 

Woodall, and Todd A. Morgan

United States 

Department of 

Agriculture

Forest Service

Pacific Northwest 

Research Station

General Technical 

Report

PNW-GTR-622

November 2004
The Forest Service of the U.S. Department of Agriculture is dedicated to the principle of 

multiple use management of the Nation’s forest resources for sustained yields of wood, 

water, forage, wildlife, and recreation. Through forestry research, cooperation with the 

States and private forest owners, and management of the National Forests and National 

Grasslands, it strives—as directed by Congress—to provide increasingly greater service to 

a growing Nation.

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and employees.

Authors

Carl E. Fiedler is a research silviculturist and Christopher W. Woodall was 

a research associate, School of Forestry, University of Montana, Missoula, MT 

59812; Charles E. Keegan III is a forest industry analyst and Todd A. Morgan

is a research forester, Bureau of Business and Economic Research, University of 

Montana, Missoula, MT 59812. Woodall currently is located at the U.S. Department 

of Agriculture, Forest Service, North Central Research Station, 1992 Folwell Ave., 

St. Paul, MN 55108.

Funding for this project was provided by the Joint Fire Science Program through a 

Research Joint Venture Agreement with the USDA Forest Service Pacific Northwest 

Research Station. 
Abstract

Fiedler, Carl E.; Keegan, Charles E., III; Woodall, Christopher W.; Morgan, 

Todd A. 2004. A strategic assessment of crown fire hazard in Montana: potential 

effectiveness and costs of hazard reduction treatments. Gen. Tech. Rep. PNWGTR-622. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific 

Northwest Research Station. 48 p.

Estimates of crown fire hazard are presented for existing forest conditions in 

Montana by density class, structural class, forest type, and landownership. Three 

hazard reduction treatments were evaluated for their effectiveness in treating historically fire-adapted forests (ponderosa pine (Pinus ponderosa Dougl. ex Laws.), 

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), dry mixed conifer) that rate 

high/moderate for fire hazard. Comprehensive restoration treatments that address 

density, structure, and species composition of high-hazard forests are significantly 

more effective at reducing hazard than thin-from-below approaches that remove 

smaller trees only. Trees removed as a byproduct of the restoration treatment 

yielded net revenues averaging over $600 per acre, whereas the thin-from-below 

approach would require an out-of-pocket expenditure of over $600 per acre. Posttreatment conditions were projected forward 30 years and reevaluated for hazard. 

Projections revealed that effectiveness of all treatments diminished over time; however, forests receiving the comprehensive restoration treatment remained substantially lower hazard 30 years after treatment than they would have had they received 

the alternative treatments.

Keywords: Montana, wildfire, forest inventory, forest restoration, Forest Inventory and Analysis, hazard reduction, treatments, costs.
Summary

Severe and extensive wildfires in the summers of 2000 and 2003 illustrate the hazardous conditions extant over large areas of the Montana landscape. These wildfires 

have heightened public interest in management actions to address fire hazard. However, developing plans to address hazard at a strategic level requires a fundamental 

understanding of the problems at hand and the potential effectiveness and costs of 

treatments to address them.

Consequently, we designed this study to:

• Profile forest conditions in Montana.

• Assess fire hazard.

• Evaluate effectiveness of hazard reduction treatments.

• Estimate treatment costs.

We used Forest Inventory and Analysis data for the state of Montana to profile 

forest conditions statewide and then assess fire hazard. We evaluated fire hazard 

by using the Fire and Fuels Extension (FFE) to the Forest Vegetation Simulator 

(FVS). Hazard was quantified in terms of crowning index, which is the windspeed 

necessary to sustain a crown fire once a fire has reached the main canopy. Crowning index values less than 25 mph were rated high hazard, 25 to 50 mph as moderate hazard, and greater than 50 mph as low hazard. For purposes of this report, fire 

hazard rating is a quantified estimate of the potential fire behavior for a fuel type 

and is based on physical characteristics such as fuel arrangement, fuel load, and 

presence of elevated fuels. Fire hazard conditions are the fuel characteristics associated with a given fire hazard rating.

Fire hazard was evaluated for nine major forest types; however, our analysis 

primarily focused on short-interval, fire-adapted ecosystems. In Montana, these are 

the high/moderate-hazard ponderosa pine, Douglas-fir, and dry lower mixed-conifer 

forests where people and property are most at risk.

We collaborated with representatives from federal, state, tribal, and industrial 

land management entities to develop three treatment prescriptions for reducing fire 

hazard:

1. Thin from below. Remove trees up to 9 inches in diameter.

2. Fifty percent basal area removal. Remove the smaller half of basal area.

3. Comprehensive. Reserve a target basal area of 40 to 50 ft2/ac, primarily 

composed of larger trees.

Fire hazard (i.e., crowning index) for each of the three treatments was evaluated immediately after treatment by using FFE. Treatment costs and revenues were 

estimated by using a harvest cost model and long-term databases maintained at the 
University of Montana. Land management agencies and the private sector provided 

cost estimates for treating fuels resulting from management activities.

We used FVS to project posttreatment conditions forward 30 years for each 

of the treatment alternatives and then reevaluated crowning index again in 2030 

by using FFE. Projection allowed us to evaluate the durability of hazard reduction 

treatments through time.

Montana has nearly 22.3 million acres of forest lands, 82 percent of which have 

a high/moderate fire hazard rating. Nearly 9.3 million acres are classified as shortinterval, fire-adapted ecosystems. About 7.5 million acres (or 80 percent) of these 

rated high/moderate for crown fire hazard.

Our analysis showed that hazard reduction treatments differed dramatically in 

their potential to reduce crown fire hazard. The thin-from-below treatment only increased average crowning index in treated stands from 27 to 34 mph, moving only 

13 percent of treated acres into the low-hazard category. The comprehensive treatment, in contrast, increased average crowning index to 82 mph, moving 90 percent 

of treated acres into a low-hazard condition. 

We also found that the comprehensive prescription designed to reduce hazard 

and restore sustainable stand conditions would yield average positive net revenues 

of $675 per acre treated. Some stands would require expenditures, but the value 

of timber products removed would cover harvest, onsite fuel treatment, and haul 

costs on over half of the acres treated. In contrast, net revenues were always negative for the thin-from-below prescription, and negative for most acres treated with 

the 50-percent basal area removal approach.

Our reevaluation of crowning index in 2030 showed that the long-term effects 

of the various hazard reduction treatments continued to differ widely. Average 

crowning index following the thin-from-below treatment nearly reverted back to the 

high-hazard category by 2030. In contrast, the average crowning index for the comprehensive treatment decreased to 64 mph, still solidly in the low-hazard category. 

Long-term effects of the 50-percent basal area removal treatment were only moderately better than those of the thin-from-below treatment.

One striking effect associated with the two prescriptions aimed at removing 

small trees is that substantial acreages would again need hazard reduction treatment 

at the end of the 30-year period. Only 3 percent of the acres receiving the thinfrom-below treatment and 10 percent receiving the 50-percent basal area removal 

treatment would remain in the low-hazard category in 2030. However, 73 percent of 

the acres treated with the comprehensive prescription would still have a low-hazard 

rating 30 years later.
Study results show that whether the fire problem is viewed from a hazard reduction, ecological condition, or financial standpoint, the comprehensive approach is 

superior to prescriptions that focus only on removing small trees. The comprehensive prescription achieves far greater hazard reduction immediately after treatment and is far less expensive to apply. It is also superior in terms of longevity and 

effectiveness. 

Highlights

• Over 80 percent of all forested lands in Montana rated high/moderate for 

crown fire hazard.

• About 9.3 million acres of Montana forest land fell within short-interval, 

fire-adapted ecosystems, 7.5 million acres of which were high/moderate 

hazard.

• Alternative treatments differed dramatically in their effectiveness in reducing crown fire hazard.

• A comprehensive prescription designed to reduce hazard and restore sustainable structure was superior to prescriptions designed to remove smaller 

trees only.

• In dense, multistoried ponderosa pine–Douglas-fir stands (Pinus 

ponderosa Dougl. ex Laws.–Pseudotsuga menziesii (Mirb.) Franco) in 

western Montana, the comprehensive treatment increased crowning index 

an average of 68 mph, whereas the thin-from-below treatment only 

increased crowning index by 2 mph.

• Ninety percent of the acres receiving the comprehensive treatment rated 

low hazard following treatment, whereas only 13 percent rated low hazard 

following the thin-from-below treatment.

• The comprehensive prescription not only provided the greatest hazard 

reduction, it also yielded an average net revenue of $675 per acre from timber removed as a treatment byproduct.

• Over 70 percent of the acres receiving the comprehensive treatment 

remained low hazard 30 years after treatment. Only 3 percent of the acres 

receiving the thin-from-below treatment were rated low hazard 30 years 

later.
Contents

 1 Introduction

 1 Methods

 2 Fire Hazard

 3 Forest Types

 3 Density and Structure

 4 Hazard Reduction Treatments

 6 Treatment Costs and Product Revenues

 7 Results and Discussion

 7 Forest Types

 9 Density and Structure

 9 Fire Hazard: Existing Conditions

 11 Fire Hazard: Treatment Effectiveness

 13 Financial Aspects of Hazard Reduction Treatments

 18 Conclusion

 19 Acknowledgments

 19 Metric Equivalents

 19 Literature Cited

 22 Appendix

1

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Introduction

Severe “fire years” in Montana in 1988 and 1994, and most recently in 2000 and 

2003, illustrate the hazardous forest conditions that exist over large areas of the 

Montana landscape. The fires of 2000 are especially notable, not just in terms of 

acres burned, but particularly because of the significant damage to property and 

associated threats to people.

Four major fire seasons in just 16 years have intensified public and agency 

concerns about wildfire. There are now both the public support and political will for 

major initiatives to address this regional concern (Devlin 2001, Western Governors’ 

Association 2001). However, planning to address fire hazard at a strategic level 

requires a fundamental understanding of the nature and scope of the problem. For 

example, what forest types and conditions are most vulnerable to fire? What kinds 

of treatments are most effective in reducing fire hazard, and how much do they 

cost? How durable are the effects of these treatments?

Absence of a detailed, systematic, and uniform forest inventory for all acres 

and ownerships has until now precluded a comprehensive analysis of fire hazard in 

Montana. However, recent availability of Forest Inventory and Analysis (FIA) data 

across all ownerships makes possible a strategic assessment of fire hazard at the 

statewide level and is the basis for the analysis that follows.

The overall goals of our project were to profile forest conditions and fire hazard 

in Montana and evaluate the potential effectiveness and costs of hazard reduction 

treatments. Specific objectives were to:

• Describe and quantify forest conditions in Montana and rate conditions for 

fire hazard.

• Develop treatment prescriptions and evaluate their effectiveness at reducing 

hazard, both now and 30 years into the future.

• Determine harvest and prescribed burning costs associated with treatment.

• Determine the potential revenue from timber products generated by the 

hazard reduction treatments.

Methods

The FIA data on the composition and condition of forest lands in Montana were 

obtained from the USDA Forest Service Interior West Forest Inventory and Analysis (IWFIA) program based in Ogden, Utah. This unit conducts permanent plot 

inventories in Montana and other Rocky Mountain states.

The National Forest System (NFS) inventory data used in this study were collected between 1993 and 1997 for western Montana, and between 1996 and 1998 for 

Four major fire seasons 

in just 16 years have 

intensified public and 

agency concerns about 

wildfire. 
2

 GENERAL TECHNICAL REPORT PNW-GTR-622

eastern Montana, and included both nonreserved and reserved lands (i.e., wilderness). The inventory of non-NFS lands occurred between 1988 and 1989 and was 

conducted on nonreserved lands only. Thus National Park Service lands were not 

included in the inventory nor were reserved lands managed by the USDI Bureau of 

Land Management, U.S. Fish and Wildlife Service, state of Montana, or Confederated Salish and Kootenai Tribes.

The most important characteristics of IWFIA data are their uniformity and 

comprehensiveness. Although forest conditions can differ greatly, the IWFIA data 

set allows description and comparison within and across regions and ownerships by 

using common measures gathered through consistent, scientific sampling methods.

We worked with data from 1,936 sample plots in western Montana and 1,807 

plots in eastern Montana. A sample plot was our basic unit of analysis. Each plot 

was regarded as a stand and typically represents about 6,000 acres of forest lands. 

Variables recorded at each sample plot fall into one of four categories:

• Location variables: owner, elevation, distance to road.

• Condition variables: condition class, slope, aspect, land use.

• Tree and stand variables: diameter, height, basal area, volume, species.

• Understory vegetation variables: cover of three vegetative layers, i.e., tree 

cover, shrub cover, forb cover; also grass cover. 

Fire Hazard

Potential fire hazard was analyzed for each plot by using the Fire and Fuels Extension (FFE) (Beukema et al. 1997, Scott and Reinhardt 2001) to the Forest Vegetation 

Simulator (FVS) (Crookston and Havis 2002, Wykoff et al. 1982). This model (extension) estimates crown fire hazard based on tree, stand, and site characteristics, 

and expresses fire hazard and effects in terms of crowning index, torching index, 

and basal area mortality.

Crowning index, defined as the windspeed necessary for a fire that reaches the 

canopy to continue as a crown fire, was the primary variable used to report hazard in this study. Crowning index is primarily determined by canopy bulk density, 

which is the density of 1-hr fuels (i.e., <1⁄4-in twigs and needles). Forest structures 

with low crowning indexes require relatively low windspeeds to maintain spreading 

crown fires, whereas structures with high crowning indexes are relatively resistant 

to crown fires. We defined high-hazard forest conditions as having a crowning 

index of <25 mph, moderate hazard from 25 to 50 mph, and low hazard >50 mph. 

Actual crowning index values should be interpreted cautiously because forest and 

weather conditions are variable. However, because modeling assumptions were the 

same for the three treatments evaluated, relative differences in crowning indexes 
3

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

among posttreatment conditions are instructive. Once the crowning index was 

calculated for each plot, the entire inventory was sorted by various combinations of 

forest type, density, structure, region, and ownership to display fire hazard by the 

categories of interest. In addition, the FVS model was used to project forest conditions 30 years into the future (i.e., from 2000 to 2030), at which time fire hazard 

was again assessed by using FFE. 

Forest Types

Conditions differ greatly across the millions of acres and approximately 7,000-ft 

elevation range of forest lands in Montana. We classified these diverse conditions 

into forest types that would be recognizable and meaningful to managers. We used 

a hierarchical model to assign each of the more than 3,700 FIA sample plots in 

Montana to one of nine forest types or one of two miscellaneous categories. Forest 

type assignments were based on majority (or plurality) basal area composition of 

key tree species and on habitat type (Pfister et al. 1977) criteria. Any plot not meeting minimal requirements for any of the nine forest type designations was classified 

as either “other” or “nonstocked,” depending on specific attributes.

Density and Structure

The FIA plots (stands) were assigned to one of three density categories (low, moderate, or high) by using a three-step process. Data were first sorted by region (west 

vs. east of the Continental Divide) and then by forest type within region. Finally, 

density classes were formulated by subdividing the population of plots within each 

region/forest type combination into thirds based on the full range of basal area densities for that combination. Thus low-density conditions as classified for this analysis are likely higher than the low density for a given forest type based on historical 

conditions; instead they fall within the lowest one-third of existing densities for that 

forest type and region (e.g., ponderosa pine, east side). 

Each FIA plot was assigned to one of four structural classes (scattered, one 

story, two story, or multistory). We formulated structural classes for each forest type 

primarily based on size class and basal area attributes. Five general size classes 

of trees were recognized: sapling (<5.0 in diameter at breast height [d.b.h.], pole 

(5 to 8.9 in d.b.h.), medium (9 to 14.9 in d.b.h.), large (15 to 19.9 in d.b.h.), and very 

large (>20.0 in d.b.h.). Plots with <25 ft2/ac of basal area were assigned to scattered 

structures as such conditions are too open to recognize distinct layers or strata. 

Plots with only one recognizable size class were categorized as one-storied structures, plots with two distinct size classes were categorized as two-storied structures, and plots with three or more size classes were categorized as multistoried 

structures. A minimum basal area of 10 ft2/ac was required for pole, medium, large, 
4

 GENERAL TECHNICAL REPORT PNW-GTR-622

or very large size classes to be recognized as an individual size class or stratum. 

For saplings, a minimum of 5 ft2/ac was required to be recognized as a distinct 

size class.

Hazard Reduction Treatments

We focused our evaluation of fire hazard on short-interval, fire-adapted ecosystems. 

In Montana, these ecosystems are primarily composed of ponderosa pine (PP), 

Douglas-fir (DF), and dry lower mixed-conifer (DLMC) forest types. Short-interval, fire-adapted ecosystems were identified as highest priority for treatment in 

Protecting People and Sustaining Resources in Fire-Adapted Ecosystems—

A Cohesive Strategy (USDA FS 2000, USDI 2001). Historically, frequent lowintensity fires were the primary agent that shaped these forests and kept them resistant to severe fires.

Although dense, multistoried conditions are a primary concern in short-interval, fire-adapted ecosystems, they are neither unexpected nor uncommon in the 

moist lower mixed-conifer, upper mixed-conifer, and spruce-fir forest types. Fires 

typically occur in these forests at relatively long intervals and burn with high severity when they do occur (Fischer and Bradley 1987). Wildfires in moister and higher 

elevation forests are not as often a direct threat to people or property and historically burned as mixed-intensity or stand-replacement events when they did occur 

(Fischer and Bradley 1987). Consequently, short-interval, fire-adapted forests were 

deemed highest priority for detailed evaluation by the technical contact team for 

this study.1

Three general types of hazard reduction treatments were evaluated. A common objective of all three is to reduce density and create a discontinuity in the 

vertical fuel profile by removing the ladder fuel component, typically composed of 

sapling- and pole-sized trees. One such approach is thinning from below to some 

given diameter limit, a treatment that has been widely recommended.2 3 We used a 

diameter limit of 9 inches in this analysis. This treatment is hereafter referred to as 

TB9. Because the primary objective of the TB9 treatment is to reduce or remove the 

ladder fuel layer, rather than substantially reduce overall stand density, this treatment was only applied to stands that had greater than 50 ft2

/ac of trees larger than 

1 The technical contact team served in an advisory capacity for this study. Members had expertise in the areas of inventory, fire management, and hazard reduction treatments, and represented state and federal government, Indian tribes, forest industry, and private landowners.

2Babbitt, B. 1997. A coordinated campaign: fight fire with fire. Speech delivered at Boise State 

University, Boise, Idaho. U.S. Department of the Interior, Washington, DC.

3Dombeck, M. 1997. Statement to Senate Committee on Energy and Natural Resources, 

Feb. 25, 1997. Washington, DC: U.S. Congress.
5

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

9 in. Indeed, a primary reason for selecting the thin-from-below approach is to 

avoid cutting larger trees or creating open stand conditions. Put another way, any 

stand that would not have at least 50 ft2/ac of basal area remaining after receiving 

the TB9 treatment was not considered for treatment.

A second approach is to remove some given percentage of the existing basal 

area (e.g., 33 to 50 percent) from the smallest trees on up (Martin 2000). A target of 

50-percent removal was used in this analysis. This treatment is hereafter referred to 

as 50-percent BA. This approach tempers potential criticism associated with 

cutting larger trees in a stand or creating open stand conditions. Hence, any stand 

that would not have at least 50 ft2/ac of basal area remaining after receiving the 

50-percent BA treatment was not considered for treatment.

A third general approach focuses on restoring sustainable structure (and 

ultimately ecological function), and therefore focuses on the trees to leave in terms 

of a target density, diameter distribution, and species composition (Fiedler et al. 

1999). Trees are marked for leave to a target basal area density of 40 to 50 ft2/ac in 

the sizes, numbers, species, and juxtaposition that will go furthest toward restoring a sustainable structure, given existing stand conditions. This ecologically based 

prescription preferentially reserves larger ponderosa pine (Pinus ponderosa Doug. 

ex Laws.) and western larch (Larix occidentalis Nutt.), which are especially fire 

resistant. It also reduces density sufficiently to induce regeneration of shade-intolerant ponderosa pine, promote development of large-diameter trees, and increase 

survival and vigor of old-growth trees (Fiedler 2000, Fiedler et al. 1988). Most of 

the 40- to 50-ft2/ac target reserve density is composed of larger trees, although 

some trees are marked for leave throughout the diameter distribution (if available) 

to provide large-tree recruits for the future. A low thinning is used to remove smalltree ladder fuels, and improvement/selection cutting is applied in the mid and upper 

canopy to reduce crown fire hazard, remove late-successional species (if present), 

and promote regeneration of ponderosa pine or western larch. This treatment is 

hereafter referred to as the comprehensive restoration treatment or CR.

All three prescriptions were applied to the PP, DF, and DLMC forest types. 

The TB9 and 50-percent BA prescriptions were applied similarly in all three forest 

types. However, the CR treatment prescription differed slightly among types, with a 

target reserve density of 40, 45, or 50 ft2/ac for the PP, DLMC, and DF forest types, 

respectively. The target reserve density could not always be retained because of 

existing diameter distributions and hazard reduction considerations. For example, 

somewhat lower reserve densities (20 to 40 ft2/ac) occasionally resulted in the DF 

type in stand conditions with relatively small numbers of larger trees. Although all 

large and medium-sized trees were retained in these cases, the summed density of 
6

 GENERAL TECHNICAL REPORT PNW-GTR-622

all reserved trees was less than the target because the basal area of small trees that 

could be reserved was capped at 2.5 ft2/ac for 4- to 8-in trees and 0.5 ft2/ac for 0- to 

4-in trees, respectively, for hazard reduction reasons.

Treatment Costs and Product Revenues

We did not consider treatment costs or potential timber product revenues when 

selecting or developing the alternative hazard reduction treatments for this study. 

The treatments we evaluated are either commonly used for hazard reduction or were 

designed specifically to reduce hazard and enhance sustainability. However, because 

cost is a major factor influencing the potential implementation of hazard reduction 

treatments, we analyzed costs after the prescriptions were developed and modeled. 

In calculating net revenue, we examined both treatment cost and the potential value 

of timber generated as a byproduct of treatments.

Treatment costs—

Costs associated with implementing hazard reduction treatments include costs of 

removing timber to reduce fuel loading, slashing activity fuels, and prescribed burning of slash. Treatment units were assumed to be operational in size (>20 ac). We 

estimated harvest and haul costs by using a recently completed predictive logging 

cost model applicable to hazard reduction and restoration treatments in Montana 

(BBER 2001a, Keegan et al. 2002). We assumed treatments would occur on sites 

already accessed; therefore, no road-building costs were included in the analyses. 

Data gathered from land management agencies and the private sector provided 

an additional basis for estimating costs associated with treating activity fuels. 

Estimated costs for hand piling and burning trees less than 5 in d.b.h. ranged from 

$50 to $280 per acre depending on tree density; cost of removing unmerchantable 

trees 5 in d.b.h. and greater ranged from under $100 per acre to over $1,000 per acre, 

depending on stand condition and logging system.

Timber product values—

Previous work shows that comprehensive prescriptions designed to reduce hazard 

and restore structure require removal of trees ranging from 4 to >20 inches in diameter (Fiedler et al., 1999, 2001). Trees in this size range have two major product uses, 

sawtimber and pulpwood (Keegan et al. in press). Sawtimber is defined as trees that 

are of a size and quality suitable for lumber production. In Montana, sawtimber includes trees ≥10 in d.b.h. The major uses of sawtimber in Montana are saw logs for 

lumber production and veneer logs for plywood. Pulpwood is timber used to produce 

chips for pulp manufacture, and in Montana is generally composed of material <10 

in d.b.h.
7

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

We developed sawtimber tree values for 1-in d.b.h. classes by major species or 

species’ groups from an extensive log price data system maintained by the University of Montana Bureau of Business and Economic Research (BBER 2001b) and 

from a sawmill simulation model (Wagner et al. 1998, 2000).

We analyzed product values under a sawtimber market scenario based on 

lumber and plywood prices from 1997 through 1999. This was a period of mixed 

conditions, with very strong markets in the first half of 1997 and most of 1999, and 

substantially weaker markets in 1998 owing to the Asian financial crisis. Historically, the market for roundwood pulpwood has been very sporadic, and at times, 

nonexistent. For this reason, we assumed 1997–99 sawtimber market conditions in 

our analysis, without a pulpwood market. Adjustments also were made to reflect 

lower values for certain species in eastern Montana.

The relationship between milling capacity and the volume of timber available 

to the industry was assumed to remain constant under all market conditions. If a 

significant proportion of acres rated high/moderate for fire hazard were treated over 

a short period, large volumes of additional material could potentially come on the 

market, thus dampening prices. However, we assumed that increases in harvested 

timber volume would phase in gradually and reach a sustainable level. This in turn 

would lead to a gradual and commensurate increase in industry size.

Results and Discussion

Forest Types

Our analysis of FIA data for Montana shows that there were approximately 

22.3 million acres of forest land in the state, 21.5 million of which were forested 

(table 1). The three forest types, PP, DF, and DLMC, of greatest management concern in terms of fire hazard collectively occupied 9.3 million acres. About 775,000 

acres were classified as “other” (OT) as they did not meet criteria for any individual 

forest type. Five of the forest types (PP, DF, lodgepole pine, moist lower mixed 

conifer, and spruce-fir) comprised at least 1 million acres each of forest land in 

Montana (table 1). Detailed breakdowns of acreages of forest types by region, ownership, density, and structure are shown in appendix tables 7a through 7d.

The federal government owns 14.8 million acres (69 percent) of the 21.5 million 

forested acres in Montana, 25 percent is privately owned, and the remaining 6 percent is in other ownership, which includes tribal and state lands (appendix table 8). 

No clear patterns in forest conditions (i.e., density or structure) could be 

discerned by ownership alone. However, some interesting observations about the 

ownership of different forest types did surface in our analysis (appendix table 7b). 
8

 GENERAL TECHNICAL REPORT PNW-GTR-622

Table 1—Acreages of major forest types in Montana

Forest type Forest land area

 Acres

Ponderosa pine 2,841,185

Douglas-fir 6,176,632

Dry lower mixed conifer 265,688

Western larch 533,637

Lodgepole pine 4,344,061

Moist lower mixed conifer 1,375,005

Upper mixed conifer 693,436

Spruce-fir 3,867,859

Timberline 588,257

Other 774,466

 Total forested acres 21,460,226

Nonstocked 814,067

Total forest land 22,274,293

Table 2—Basal area ranges for low-, moderate-, and high-density 

classes, by fire-adapted forest type and geographic region

Basal area

Forest typea Low Moderate High

Ft 

2

/acre

West of the Continental Divide:

 PP <50 50–100 >100

 DF <90 90–150 >150

 DLMC <80 80–130 >130

East of the Continental Divide:

 PP <40 40–75 >75

 DF <80 80–130 >130

 DLMC <60 60–130 >130

aFire-adapted forest types include ponderosa pine (PP), Douglas-fir (DF), and dry 

lower mixed conifer (DLMC).
9

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

For example, only about half (54 percent) of Montana’s 9.3 million acres of shortinterval fire-adapted forests (PP, DF, DLMC types) are federally owned, whereas 

86 percent of upper mixed-conifer, 90 percent of spruce-fir, and 98 percent of timberline forests are owned by the federal government.

Density and Structure

The ranges of basal area densities that were classified as high, moderate, and low 

differed among forest types and geographic regions (west and east of the Continental Divide) (appendix table 9). Basal area density ranges for the PP, DF, and DLMC 

types are shown in table 2 to provide a frame of reference as to “How dense is 

dense?”

The 21.5 million forested acres in the state were classified within one of four 

structural types: scattered, one storied, two storied, or multistoried, with <1 percent 

of this total classified as having no structure. Approximately 9.5 million acres, or 

44 percent of the forested acres, occurred in multistoried structures. About 28, 19, 

and 9 percent occurred in two-storied, one-storied, and scattered structures, respectively (appendix table 7).

Fire Hazard: Existing Conditions

Results of our statewide analysis of crown fire hazard shows that 42 percent of 

Montana’s forests were classified as high hazard, about 40 percent as moderate 

hazard, and only 18 percent as low hazard, based on crowning index (fig. 1).

Fire hazard ratings were similar for forest lands located west and east of the Continental Divide. About 39 percent of the forest lands west of the Divide were rated 

high hazard, about 45 percent were rated moderate, and approximately 16 percent 

were low hazard. Comparable numbers for forest lands east of the Divide were 45, 

36, and 19 percent, respectively.

Existing fire hazard conditions in the 9.3 million acres of short-interval, fireadapted forests approximated those for the state as a whole. Thirty-five percent of 

the acres of fire-adapted forests were rated high hazard, 45 percent as moderate 

hazard, and 20 percent as low hazard (fig. 2). Of the nearly 5 million acres of PP, 

DF, and DLMC on federal land, 83 percent have a high/moderate fire hazard rating. 

This is in line with the fire hazard rating for these forest types across all ownerships, where 80 percent of short-interval, fire-adapted forests have a high/moderate 

fire hazard rating.

Average crowning index values by region, ownership, density, and structure 

are shown in appendix table 10. The trends in crowning index across density and 

structural classes were especially notable. For example, looking at all forest types 

combined, average crowning index declined (i.e., hazard increased) across the range 

Analysis of crown fire 

hazard shows that 42 

percent of Montana’s 

forests were classified 

as high hazard, about 

40 percent as moderate 

hazard.
10

 GENERAL TECHNICAL REPORT PNW-GTR-622

Moderate

40%

Low

18%

High

42%

Total forest land = 22.3 million acres

Figure 1—Proportion of Montana’s forest land by fire hazard rating.

Figure 2—Proportion of Montana’s short-interval, fire-adapted forest types (i.e., 

ponderosa pine (PP)/Douglas-fir (DF)/dry lower mixed conifer (DLMC)) by fire 

hazard rating.

Low

20%

Moderate

45%

High

35%

Total PP, DF, DLMC forest land = 9.3 million acres
11

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

of densities from 47 at low density to 29 at moderate density, to 21 at high density. 

Similarly, average crowning index declined (and hazard increased) with increasing 

complexity in stand structure, from 34 to 32 to 25 for one-, two-, and multistoried 

structures, respectively.

As the previous example shows, stand density is a particularly important attribute influencing crowning index. The strong effect of density is demonstrated in 

the following example. In stands with multistoried structures, 74 percent were rated 

high hazard if they were also in the high-density category, whereas only 26 percent 

of moderate-density stands and 0 percent of low-density stands in this structural 

class received a high-hazard rating. The importance of density to crowning index is 

not unexpected, given that the calculation of crowning index within FFE is primarily dependent on canopy bulk density.

Structure also had a substantial effect on crowning index in the 9.3 million 

acres of short-interval, fire-adapted forests. For example, in high-density conditions, 

74 percent of the stands with multistoried structures were rated high hazard, 

where-as only 49 and 36 percent of two- and one-storied stands received a similar 

rating, respectively.

Fire Hazard: Treatment Effectiveness

Short-term effects on fire hazard—

Hazard reduction treatments were evaluated for effectiveness if applied to the 

7.5 million acres of forests with high/moderate fire hazard in short-interval, fireadapted ecosystems (PP, DF, and DLMC forest types). Our analysis showed that 

both average crowning index and the number of potentially treatable acres differed 

by prescription. 

The effectiveness of treatments in reducing fire hazard (increasing crowning 

index) ranged from modest for the TB9 treatment to dramatic for the CR treatment 

(table 3). The TB9 treatment only increased average crowning index 7 mph, whereas the CR treatment created a 56-mph increase. The average crowning index of 

34 resulting from the TB9 treatment still left most stands in the moderate fire hazard range, and only 13 percent of treated acres moved to low hazard (table 3). The 

CR treatment, in contrast, increased average crowning index to 82 mph, well into 

the low-hazard range.

The number of forested acres potentially treatable differed as a result of 

differential silvicultural constraints placed on the three prescriptions, leading to 

slight differences among pretreatment crowning index values (table 3). An example of the constraints and their effects on acres treated can be seen in the 

differences between the TB9 and CR treatments. The TB9 prescription could be 

Stand density is a 

particularly important 

attribute influencing 

crowning index.

The effectiveness of 

treatments in reducing 

fire hazard ranged from 

modest for the TB9 

treatment to dramatic for 

the CR treatment.
12

 GENERAL TECHNICAL REPORT PNW-GTR-622

applied to 5.1 million acres of the 7.5 million acres rated high/moderate hazard, 

whereas the CR treatment could potentially be applied to as many as 6.4 million 

acres. The lower acreage associated with the TB9 treatment primarily arises from 

restrictions to cutting in stands that would not have sufficient basal area remaining 

if all trees below 9 in d.b.h. were cut (e.g., a PP stand with no trees >8 in d.b.h., or a 

DLMC stand with only 10 ft2/acres of basal area in trees >9 in). The CR treatment 

could still be applied in some of these stands as long as the target reserve basal area 

could be achieved or sufficient trees were available to serve as a seed source for 

regenerating a new age class.

Long-term effects on fire hazard—

Our evaluation of crowning index in 2030 showed that the long-term effects of the 

various fire-hazard treatments differed greatly, depending on which prescription 

was implemented. However, the effectiveness of all hazard reduction treatments 

diminished somewhat through time.

Average crowning index following the TB9 treatment reverted from moderate 

hazard (34 mph) in 2000 nearly back to the high hazard category in 2030 (table 4). 

Average crowning index for the CR treatment changed the most (numerically) over 

the 30-year period, from 82 to 64 mph, but still remained solidly in the low hazard 

category (table 4). Changes associated with the 50-percent BA treatment were intermediate to the other two treatments.

Changes in crowning index values for two of the three prescriptions indicate 

that substantial acreages would again need hazard reduction treatment at the end 

of the 30-year period. Only 3 percent of the acres receiving the TB9 treatment and 

10 percent receiving the 50-percent BA treatment would remain in the low hazard 

Table 3—Effects of hazard reduction treatments in fire-adapted forest typesa

Pretreatment Posttreatment Treated acres High/moderate

crowning crowning rated low hazard hazard acres

Hazard reduction treatment index index posttreatment treated

 - - - - - - Mph (SD)b - - - - - - Percent Million acres

Thin from below (TB9) 27 (9.5) 34 (14.9) 13 5.1 

50-percent basal area removal 25 (9.0) 50 (18.9) 44 5.2

 (50-percent BA)

Comprehensive restoration (CR) 26 (9.5) 82 (31.7) 90 6.4

aFire-adapted forest types include ponderosa pine (PP), Douglas-fir (DF), and dry lower mixed conifer (DLMC).

bSD = standard deviation.

The long-term effects of 

the various fire-hazard 

treatments differed 

greatly. However, 

the effectiveness of 

all hazard reduction 

treatments diminished 

somewhat through time.
13

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

category in 2030 (table 4). Meanwhile, 73 percent of the acres treated under the CR 

prescription would retain a low hazard rating 30 years after initial treatment.

The distribution of acres by crowning index values before treatment in 2000, 

after treatment in 2000, and in 2030 (fig. 3) shows that only the CR prescription 

provided lasting hazard reduction for treated stands. Differences are striking and 

further illustrate the relative short- and long-term ineffectiveness of prescriptions 

aimed only at removing small trees.

Financial Aspects of Hazard Reduction Treatments

The three hazard reduction treatments differed greatly in terms of the volumes 

and value of timber products recovered in the process of treatment implementation. Based on 1997–99 market conditions, applying the TB9 prescription required 

an average expenditure of $669 per acre (table 5), and all acres treated with this 

prescription required expenditure to underwrite treatment costs (table 6, fig. 4). Application of the 50-percent BA prescription required an average expenditure of $287 

per acre. A small proportion (20 percent) of the acres yielded timber product values 

sufficient to cover treatment costs. Applying the CR treatment prescription to those 

short-interval, fire-adapted forest acres with a high/moderate fire hazard rating 

yielded an average revenue of $675 per acre treated (table 5). The range of revenues 

was substantial, with some stands costing over $1,000 per acre to treat and others 

yielding positive net revenues of more than $2,000 per acre (fig. 4). More than half 

of the acres treated with the CR prescription yielded a value in timber (as treatment 

byproduct) that exceeded all onsite hazard treatment costs (table 6, fig. 4). 

Net revenues (+ or -) associated with implementing a given prescription differed substantially between forests located west and east of the Continental Divide. 

Table 4—Immediate (2000) and long-term (after 30 years) effects of hazard reduction treatments in 

fire-adapted forest typesa

Average crowning Average crowning Treated acres rated

index immediately index 30 years low hazard 30 years 

Hazard treatment reduction after treatment after treatment after treatment

 - - - - - - - - - Mph (SD)b - - - - - - - - Percent

Not treated 26 (9.5) 26 (7.4) <1

Thin from below (TB9) 34 (14.9) 30 (9.0) 3

50-percent basal area removal 50 (18.9) 38 (9.9) 10

 (50-percent BA)

Comprehensive restoration (CR) 82 (31.7) 64 (22.4) 73

aFire-adapted forest types include ponderosa pine (PP), Douglas-fir (DF), and dry lower mixed conifer (DLMC). 

bSD = standard deviation. 

More than half of the 

acres treated with the 

CR prescription yielded 

a value in timber (as 

treatment byproduct) 

that exceeded all onsite 

hazard treatment costs. 
14

 GENERAL TECHNICAL REPORT PNW-GTR-622

Thin from below (TB9)

Thousand acres

Crowning index (mph)

2,800

2,400

2,000

1,600

1,200

800

400

0

0–10

10–20

20–30

30–40

40–50

50–60

60–70

70–80

80–90

90+

Pretreatment

Posttreatment, year 0

Posttreatment, year 30

Thousand acres

Crowning index (mph)

2,800

2,400

2,000

1,600

1,200

800

400

0

0–10

10–20

20–30

30–40

40–50

50–60

60–70

70–80

80–90

90+

Pretreatment

Posttreatment, year 0

Posttreatment, year 30

50-percent basal area reduction (50-percent BA)

Thousand acres

Crowning index (mph)

2,800

2,400

2,000

1,600

1,200

800

400

0

0–10

10–20

20–30

30–40

40–50

50–60

60–70

70–80

80–90

90+

Pretreatment

Posttreatment, year 0

Posttreatment, year 30

Comprehensive restoration (CR)

Figure 3—Distribution of acres by crowning index values pretreatment, posttreatment year 0, and 

posttreatment year 30, for three hazard reduction treatments.
15

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Stands west of the Divide had higher pretreatment volumes; therefore, substantially 

higher volumes of trees with commercial value were removed to achieve desired 

objectives. As a result, application of the CR treatment netted an average of $900 

more per acre in west-side forests than east-side forests (table 5). Under the CR 

treatment, timber product values exceeded treatment costs on 61 percent of the 

west-side acres, compared to only 40 percent east of the divide (table 6).

Because stands in western Montana also supported a greater number of small 

trees with little or no product value, the average cost of applying the TB9 treatment was $166 per acre higher ($743 vs. $577) in west- versus east-side forests (fig. 

5, table 5). Conversely, there was little difference in costs ($311 vs. $266 per acre) 

west and east of the Continental Divide for the 50-percent BA treatment (table 5). 

Several market conditions were evaluated, and different market assumptions 

resulted in different costs and revenues associated with the alternative treatment 

prescriptions. However, fundamental differences among treatments did not change 

under the various market scenarios. For example, inclusion of a roundwood pulpwood market—which provides an improved outlet for smaller material—improved 

the financial aspect of all the treatments. Under the pulpwood scenario, the TB9 and 

50-percent BA treatments required smaller (though still substantial) expenditures to 

implement, whereas the CR prescription yielded even greater positive revenues.

Table 5—Net revenues per acre by hazard reduction treatment for fire-adapted forest 

types and 1997–99 market conditionsa

Hazard reduction treatment Statewide West side East side

Thin from below (TB9) -$669 -$743 -$577

50-percent basal area removal (50-percent BA) -$287 -$266 -$311

Comprehensive restoration (CR) $675 $1,103 $196

aFire-adapted forest types include ponderosa pine (PP), Douglas-fir (DF), and dry lower mixed conifer (DLMC).

Table 6—Percentage of treated acres with positive net revenues by hazard reduction 

treatment for fire-adapted forest types and 1997–99 market conditionsa

Hazard reduction treatment Statewide West side East side

Percent

Thin from below (TB9) 0 0 0

50-percent basal area removal (50-percent BA) 20 23 17

Comprehensive restoration (CR) 51 61 40

aFire-adapted forest types include ponderosa pine (PP), Douglas-fir (DF), and dry lower mixed conifer (DLMC).
16

 GENERAL TECHNICAL REPORT PNW-GTR-622

Figure 4—Distribution of acres by net revenue and hazard reduction treatment for high/moderate hazard conditions in 

ponderosa pine, Douglas-fir, dry lower mixed conifer forest types (1997–1999 market conditions).

Thin from below (TB9)

Thousand acres

2,000

1,600

1,200

800

400

0

<-1,000

-1,000–800 

-800–600-600–400-400–200

-200–0

0–200

200–400400–600

600–800

800–1,000

1,000+

50-percent basal area reduction (50-percent BA)

Thousand acres

2,000

1,600

1,200

800

400

0

<-1,000

-1,000–800 

-800–600-600–400-400–200

-200–0

0–200

200–400

400–600600–800

800–1,000

1,000+

Comprehensive restoration (CR)

Thousand acres

2,000

1,600

1,200

800

400

0

<-1,000

-1,000–800 

-800–600-600–400-400–200

-200–0

0–200

200–400400–600600–800

800–1,000

1,000+

Costs or revenues (dollars per acre)
17

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Figure 5—Distribution of acres by net revenue and hazard reduction treatment for high/moderate hazard conditions in ponderosa pine, Douglas-fir, dry lower mixed-conifer forest types, east and west of the Continental Divide 

(1997–99 market conditions).

Thin from below (TB9)

Thousand acres

1,200

1,000

800

600

400

0

200

<-1,000

-1,000–800 

-800–600-600–400-400–200

-200–0

0–200

200–400

400–600

600–800

800–1,000

1,000+

East side

West side

50-percent basal area reduction (50-percent BA)

Thousand acres

1,200

1,000

800

600

400

0

200

<-1,000

-1,000–800 

-800–600-600–400-400–200

-200–0

0–200

200–400

400–600

600–800

800–1,000

1,000+

Comprehensive restoration (CR)

Thousand acres

1,200

1,000

800

600

400

0

200

Costs or revenues (dollars per acre)

<-1,000

-1,000–800 

-800–600

-600–400

-400–200

-200–0

0–200

200–400

400–600

600–800

800–1,000

1,000+
18

 GENERAL TECHNICAL REPORT PNW-GTR-622

Conclusion

It is critical that managers carefully review options before applying hazard reduction treatments. Considerable money and effort can be expended with little improvement in fire hazard or ecological condition. For example, applying the TB9 

treatment that removes only trees 9 in and smaller from hazardous stand conditions 

is expensive, yet has little effect on lowering crown fire hazard. In the dense, twoand multistoried stands in western Montana where fire hazard is greatest, average 

crowning index was only 2 to 3 mph higher after receiving the TB9 treatment than 

before. These results underscore the importance of evaluating pre- and posttreatment conditions (stand tables) for crowning index during the process of prescription 

development.

Our results demonstrate that a treatment approach that focuses on restoring 

sustainable forest structure (and ultimately ecological function) in fire-adapted forests is often dramatically superior to thin-from-below treatments in reducing crown 

fire hazard. The CR approach evaluated in this analysis identifies a desired future 

range of conditions, evaluates the existing stand, and reserves trees in the sizes, 

numbers, and species that make the most progress toward these desired conditions. 

Put another way, trees that do not contribute to this objective are removed from the 

stand—they are a byproduct of the CR treatment. Hazard reduction prescriptions, 

in contrast, commonly start with the premise that fire hazard is essentially a onedimensional, small-tree problem, and therefore prescribe the removal of variable 

amounts of small trees to address it. However, our evaluation of crown fire hazard following treatment shows that these small-tree removal prescriptions do not 

achieve their stated objective. Although removing small trees is a necessary part of 

any effort to reduce hazard, this analysis clearly shows that by itself, it is not sufficient.

The CR treatment, with multiple ecologically based objectives, moves 90 percent of treated acres into a low-hazard condition following treatment. In addition, 

removing late-successional species and reducing density sufficiently to induce seral 

species regeneration (and enhance sustainability) commonly require cutting some 

medium-sized and larger trees with commercial value, which on average yield 

enough revenue to cover treatment costs. Hazard reduction effects are also longer 

lasting, with over 70 percent of treated stands remaining in a low-hazard condition 

30 years after treatment.

It is critical that 

managers carefully 

review options before 

applying hazard 

reduction treatments. 

Considerable money 

and effort can be 

expended with little 

improvement in fire 

hazard or ecological 

condition.
19

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Acknowledgments

We thank Sharon Woudenberg, USDA FS Rocky Mountain Research Station 

(RMRS), for valuable help in interpreting FIA data; Steve Robertson, University of 

Montana School of Forestry, for his major contribution in data analysis; Joe Scott, 

contractor with the Fire Effects project at the RMRS Fire Sciences Laboratory in 

Missoula, for insights in using and interpreting the Fire and Fuels Extension; and 

John Chmelik, for help in summarizing and classifying FIA data. We also thank 

technical contact team members Donald Artley, Montana Department of Natural 

Resources and Conservation; Danny Castillo, USDA FS Northern Region; Dennis 

Dupuis, Salish and Kootenai Tribal Forestry (now with the Bureau of Indian Affairs National Interagency Fire Center); Bruce Reid, Bureau of Land Management; 

and Gordy Sanders, Montana Tree Farmers and forest industry. Finally, we thank 

Jamie Barbour and Roger Fight, USDA FS PNW Research Station; Ron McRoberts, 

USDA FS North Central Research Station; and Sharon Woudenberg, USDA FS 

RMRS, for review comments.

Metric Equivalents

When you know: Multiply by: To get:

Inches (in) 2.54 Centimeters

Feet (ft) .3048 Meters

Miles per hour (mph) 1.609 Kilometers per hour

Acres (ac) .405 Hectares

Square feet (ft2) .0929 Square meters

Square feet per acre (ft2/ac) .229 Square meters per hectare

Literature Cited

Beukema, S.J.; Greenough, D.C.; Robinson, C.E. [et al.]. 1997. An introduction 

to the Fire and Fuels Extension to FVS. In: Teck, R.; Moeur, M.; Adams, J., eds. 

Proceedings of the Forest Vegetation Simulator conference. Gen. Tech. Rep. INT373. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain 

Forest Range and Experiment Station: 191–195.

Bureau of Business and Economic Research. [BBER] 2001a. Harvest cost data 

system: database. Missoula, MT: The University of Montana. 

Bureau of Business and Economic Research [BBER]. 2001b. The log price 

reporting system: database. Missoula, MT: The University of Montana.
20

 GENERAL TECHNICAL REPORT PNW-GTR-622

Crookston, N.L.; Havis, R.N., comps. 2002. Second Forest Vegetation Simulator 

conference. Proc. RMRS-P-25. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Research Station. 208 p.

Devlin, S. 2001. Bitterrooters want action on burned land. Missoulian. http://www.

missoulian.com/specials/fires2001/resources/timber-042801.html. (April 28).

Fiedler, C.E. 2000. Understanding the ecosystem: its parts and processes—

silvicultural treatments. In: Proceedings: The Bitterroot Ecosystem Management 

Research Project: what we have learned. RMRS-P-17. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research Station: 

19–20.

Fiedler, C.E.; Arno, S.F.; Keegan, C.E.; Blatner, K.A. 2001. Overcoming 

America’s wood deficit: an overlooked option. BioScience. 51: 53–58.

Fiedler, C.E.; Becker, R.; Haglund, S. 1988. Preliminary guidelines for unevenaged silvicultural prescriptions in ponderosa pine. In: Baumgartner, D.; Lotan, 

J., eds. Ponderosa pine: the species and its management. Proceedings. Pullman, 

WA: Washington State University Cooperative Extension: 235–241.

Fiedler, C.E.; Keegan, C.E.; Arno, S.F.; Wichman, D.P. 1999. Product and 

economic implications of ecosystem restoration. Forest Products Journal. 

49: 19–23.

Fischer, W.C.; Bradley, A.F. 1987. Fire ecology of western Montana habitat types. 

Gen. Tech. Rep. GTR-INT-223. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Research Station. 95 p.

Keegan, C.E.; Gebert, K.; Chase, A.L.; Morgan, T.A.; Bodmer, S.E.; 

Van Hooser, D.D. [In press]. Montana’s forest products industry: a descriptive 

analysis 1969–2000. Missoula, MT: The University of Montana-Missoula, 

Bureau of Business and Economic Research.

Keegan, C.E.; Niccolucci, M.J.; Fiedler, C.E. [et al.]. 2002. Harvest cost 

collection approaches and associated equations for restoration treatments on 

national forests. Forest Products Journal. 52: 96–99.

Martin, S. 2000. Personal communication. Silviculturist, Musselshell Ranger 

District, Lewis and Clark National Forest, 809 2nd Street NW, Harlowton, MT 

59036.

Pfister, R.D.; Kovalchik, B.L.; Arno, S.F.; Presby, R.C. 1977. Forest habitat 

types of Montana. Gen. Tech. Rep. GTR-INT-34. Ogden, UT: U.S. Department 

of Agriculture, Forest Service, Intermountain Research Station. 174 p.
21

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Scott, J.H.; Reinhardt, E.D. 2001. Assessing crown fire potential by linking models 

of surface and crown fire behavior. Res. Pap. RMRS-RP-29. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research Station. 

59 p.

U.S. Department of Agriculture, Forest Service. 2000. Protecting people and 

sustaining resources in fire-adapted ecosystems—a cohesive strategy. http://www.

fs.fed.us/pub/fam/. (January 2001).

U.S. Department of the Interior. 2001. Integrating fire and natural resources 

management—a cohesive strategy for protecting people by restoring land health. 

http://fireplan.gov/references. (June 2002).

Wagner, F.G.; Fiedler, C.E.; Keegan, C.E. 2000. Processing value of smalldiameter sawtimber at conventional stud sawmills and modern, high-speed smalllog sawmills in the Western U.S—a comparison. Western Journal of Applied 

Forestry. 15: 208–212.

Wagner, F.G.; Keegan, C.E.; Fight, R.D.; Willits, S.A. 1998. Potential for smalldiameter sawtimber utilization by the current sawmill industry in western North 

America. Forest Products Journal. 48: 30–34.

Western Governors’ Association. 2001. A collaborative approach for reducing 

wildland fire risks to communities and the environment—10-year comprehensive 

strategy. http://www.westgov.org/wga/initiatives/fire/final_fire_rpt.pdf. (January 1).

Wykoff, W.R.; Crookston, N.L.; Stage, A.R. 1982. User’s guide to the Stand 

Prognosis Model. Gen. Tech. Rep. GTR-INT-133. Ogden, UT: U.S. Department of 

Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 

112 p.
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 GENERAL TECHNICAL REPORT PNW-GTR-622

Appendix Table 7a—Acres by region, forest type, density, structure Forest typea Forest structure and density PP DF WL LP DLMC MLMC UMC S/F TL Other Total

Acres

Montana: Structure— No structure 27,468 17,466 NA NA NA 12,573 NA 6,381 11,691 11,333 86,912 Scattered 487,363 454,678 124,611 259,645 28,832 85,720 29,873 318,471 71,851 70,499 1,931,543 One story 263,984 524,393 268,847 2,320,671 35,673 125,874 95,546 279,396 62,040 111,386 4,087,810 Two story 1,120,792 1,389,267 121,088 1,513,052 86,486 319,839 198,750 749,459 171,044 269,536 5,939,313 Multistoried 941,578 3,790,828 19,091 250,693 114,697 830,999 369,267 2,514,152 271,631 311,712 9,414,648 Total 2,841,185 6,176,632 533,637 4,344,061 265,688 1,375,005 693,436 3,867,859 588,257 774,466 21,460,226 Density— Low 1,114,917 2,152,151 191,595 1,415,442 74,869 546,487 220,753 1,290,458 287,521 259,343 7,553,536 Moderate 861,810 1,925,413 165,900 1,412,681 105,976 461,943 241,253 1,310,343 113,838 267,809 6,866,966 High 864,458 2,099,068 176,142 1,515,938 84,843 366,575 231,430 1,267,058 186,898 247,314 7,039,724 Total 2,841,185 6,176,632 533,637 4,344,061 265,688 1,375,005 693,436 3,867,859 588,257 774,466 21,460,226West of the Continental Divide: Structure— No structure 5,808 17,466 NA NA NA 12,573 NA 6,381 NA NA 42,228 Scattered 96,518 281,948 124,611 125,334 19,170 61,042 24,710 197,828 24,393 NA 955,554 One story 49,989 293,841 268,847 925,992 21,349 114,565 56,483 168,494 23,305 NA 1,922,865 Two story 222,303 765,746 121,088 743,312 57,895 271,452 140,402 412,516 77,643 20,374 2,832,731 Multistoried 257,203 2,244,050 19,091 86,745 95,273 709,524 257,625 1,463,165 90,455 42,509 5,265,640 Total 631,821 3,603,051 533,637 1,881,383 193,687 1,169,156 479,220 2,248,384 215,796 62,883 11,019,018 Density— Low 225,294 1,279,848 191,595 583,363 59,708 414,179 145,940 788,008 125,168 20,218 3,833,321 Moderate 210,939 1,187,226 165,900 635,562 74,797 419,427 172,054 740,294 55,477 17,649 3,679,325 High 195,588 1,135,977 176,142 662,458 59,182 335,550 161,226 720,082 35,151 25,016 3,506,372 Total 631,821 3,603,051 533,637 1,881,383 193,687 1,169,156 479,220 2,248,384 215,796 62,883 11,019,018East of the Continental Divide: Structure— No structure 21,660 NA NA NA NA NA NA NA 11,691 11,333 44,684 Scattered 390,845 172,730 NA 134,311 9,662 24,678 5,163 120,643 47,458 70,499 975,989 One story 213,995 230,552 NA 1,394,679 14,324 11,309 39,063 110,902 38,735 111,386 2,164,945
23

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Table 7a—Acres by region, forest type, density, structure (continued)

Forest typea

Forest structure and density PP DF WL LP DLMC MLMC UMC S/F TL Other Total

Acres

 Two story 898,489 623,521 NA 769,740 28,591 48,387 58,348 336,943 93,401 249,162 3,106,582 Multistoried 684,375 1,546,778 NA 163,948 19,424 121,475 111,642 1,050,987 181,176 269,203 4,149,008 Total 2,209,364 2,573,581 NA 2,462,678 72,001 205,849 214,216 1,619,475 372,461 711,583 10,441,208 Density

—

 Low 889,623 872,303 NA 832,079 15,161 132,308 74,813 502,450 162,353 239,125 3,720,215 Moderate 650,871 738,187 NA 777,119 31,179 42,516 69,199 570,049 58,361 250,160 3,187,641 High 668,870 963,091 NA 853,480 25,661 31,025 70,204 546,976 151,747 222,298 3,533,352 Total 2,209,364 2,573,581 NA 2,462,678 72,001 205,849 214,216 1,619,475 372,461 711,583 10,441,208NA = no plots recorded.a Forest type abbreviations are PP = ponderosa pine, DF = Douglas-fir, WL = western larch, LP = lodgepole pine, DLMC = dry lower mixed conifer, MLMC = moist lower mixed conifer, UMC = upper mixed conifer, S/F = spruce/fir, TL = timberline.
24

 GENERAL TECHNICAL REPORT PNW-GTR-622 Table 7b—Acres by ownership, forest type, density, structure in Montana Forest typea Forest structure and density PP DF WL LP DLMC MLMC UMC S/F TL Other Total Acres Federal: Structure— No structure 10,128 17,466 NA NA NA 12,573 NA 6,381 11,691 11,333 69,572 Scattered 211,936 269,181 90,487 167,167 15,937 61,645 12,847 286,080 71,851 40,370 1,227,501 One story 53,899 335,708 174,641 1,975,345 NA 74,386 82,821 238,250 62,040 22,079 3,019,169 Two story 318,209 885,940 77,499 1,268,220 48,765 216,292 172,518 657,836 171,044 77,461 3,893,784 Multistoried 353,460 2,397,635 12,573 203,301 62,325 548,041 325,424 2,305,797 261,276 126,258 6,596,090 Total 947,632 3,905,930 355,200 3,614,033 127,027 912,937 593,610 3,494,344 577,902 277,501 14,806,116 Density—

 Low 395,746 1,383,147 140,286 1,095,069 22,318 388,578 187,389 1,182,900 287,521 113,433 5,196,387 Moderate 277,114 1,283,409 118,485 1,277,784 66,629 364,277 230,175 1,229,864 107,643 81,389 5,036,769 High 274,772 1,239,374 96,429 1,241,180 38,080 160,082 176,046 1,081,580 182,738 82,679 4,572,960 Total 947,632 3,905,930 355,200 3,614,033 127,027 912,937 593,610 3,494,344 577,902 277,501 14,806,116Private: Structure— No structure 17,340 NA NA NA NA NA NA NA NA NA 17,340 Scattered 235,977 156,895 26,364 79,578 12,895 18,038 17,026 26,354 NA 18,172 591,299 One story 184,142 169,071 76,341 269,914 26,836 39,205 11,002 26,079 NA 61,539 864,129 Two story 652,159 442,920 30,358 192,714 28,217 82,259 22,786 61,555 NA 163,416 1,676,384 Multistoried 432,938 1,072,575 NA 40,940 33,419 206,791 30,919 137,994 4,160 153,406 2,113,142 Total 1,522,556 1,841,461 133,063 583,146 101,367 346,293 81,733 251,982 4,160 396,533 5,262,294 Density— Low 593,320 657,129 41,826 275,418 45,753 130,839 28,195 86,164 NA 101,632 1,960,276 Moderate 482,076 549,850 39,895 97,210 31,913 88,735 5,362 50,318 NA 158,681 1,504,040 High 447,160 634,482 51,342 210,518 23,701 126,719 48,176 115,500 4,160 136,220 1,797,978 Total 1,522,556 1,841,461 133,063 583,146 101,367 346,293 81,733 251,982 4,160 396,533 5,262,294Other: Structure— No structure NA NA NA NA NA NA NA NA NA NA NA Scattered 39,450 28,602 7,760 12,900 NA 6,037 NA 6,037 NA 11,957 112,743 One story 25,943 19,614 17,865 75,412 8,837 12,283 1,723 15,067 NA 27,768 204,512
25

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Table 7b—Acres by ownership, forest type, density, structure in Montana (continued)

Forest typea

Forest structure and density PP DF WL LP DLMC MLMC UMC S/F TL Other Total

Acres

 Two story 150,424 60,407 13,231 52,118 9,504 21,288 3,446 30,068 NA 28,659 369,145 Multistoried 155,180 320,618 6,518 6,452 18,953 76,167 12,924 70,361 6,195 32,048 705,416 Total 370,997 429,241 45,374 146,882 37,294 115,775 18,093 121,533 6,195 100,432 1,391,816 Density— Low 125,851 111,875 9,483 44,955 6,798 27,070 5,169 21,394 NA 44,278 396,873 Moderate 102,620 92,154 7,520 37,687 7,434 8,931 5,716 30,161 6,195 27,739 326,157 High 142,526 225,212 28,371 64,240 23,062 79,774 7,208 69,978 NA 28,415 668,786 Total 370,997 429,241 45,374 146,882 37,294 115,775 18,093 121,533 6,195 100,432 1,391,816NA = no plots recorded.a Forest type abbreviations definitions are PP = ponderosa pine, DF = Douglas-fir, WL = western larch, LP = lodgepole pine, DLMC = dry lower mixed conifer, MLMC = moist lower mixed conifer, UMC = upper mixed conifer, S/F = spruce/fir, TL = timberline.
26

 GENERAL TECHNICAL REPORT PNW-GTR-622 Table 7c—Acres by ownership, forest type, density, structure for Montana, west of the Continental Divide Forest typea Forest structure and density PP DF WL LP DLMC MLMC UMC S/F TL Other Total Acres Federal: Structure— No structure 5,808 17,466 NA NA NA 12,573 NA 6,381 NA NA 42,228 Scattered 31,073 175,659 90,487 68,806 6,275 36,967 12,847 170,600 24,393 NA 617,107 One story 18,362 165,820 174,641 750,190 NA 74,386 49,257 158,011 23,305 NA 1,413,972 Two story 89,707 436,210 77,499 587,670 36,479 179,275 123,555 359,458 77,643 6,277 1,973,773 Multistoried 93,701 1,333,566 12,573 80,293 49,455 432,282 225,122 1,362,164 86,295 NA 3,675,451 Total 238,651 2,128,721 355,200 1,486,959 92,209 735,483 410,781 2,056,614 211,636 6,277 7,722,531 Density—

 Low 95,437 814,416 140,286 462,339 12,656 278,949 123,238 736,569 125,168 6,277 2,795,335 Moderate 99,844 779,985 118,485 556,166 60,580 321,761 166,692 709,248 55,477 NA 2,868,238 High 43,370 534,320 96,429 468,454 18,973 134,773 120,851 610,797 30,991 NA 2,058,958 Total 238,651 2,128,721 355,200 1,486,959 92,209 735,483 410,781 2,056,614 211,636 6,277 7,722,531Private: Structure— No structure NA NA NA NA NA NA NA NA NA NA NA Scattered 60,693 91,628 26,364 43,628 12,895 18,038 11,863 21,191 NA NA 286,300 One story 17,402 123,081 76,341 141,897 12,512 27,896 5,503 8,760 NA NA 413,392 Two story 89,698 282,661 30,358 115,435 11,912 70,889 13,401 41,759 NA 13,941 670,054 Multistoried 105,136 641,207 NA NA 26,865 206,791 25,295 47,788 4,160 36,232 1,093,474 Total 272,929 1,138,577 133,063 300,960 64,184 323,614 56,062 119,498 4,160 50,173 2,463,220 Density— Low 94,023 388,367 41,826 100,511 40,254 108,160 17,533 41,956 NA 13,941 846,571 Moderate 84,118 328,619 39,895 53,110 6,783 88,735 5,362 19,654 NA 11,216 637,492 High 94,788 421,591 51,342 40,254 17,147 126,719 33,167 57,888 4,160 25,016 872,072 Total 272,929 1,138,577 133,063 193,875 64,184 323,614 56,062 119,498 4,160 50,173 2,356,135Other: Structure— No structure NA NA NA NA NA NA NA NA NA NA NA Scattered 4,752 14,661 7,760 12,900 NA 6,037 NA 6,037 NA NA 52,147 One story 14,225 4,940 17,865 33,905 8,837 12,283 1,723 1,723 NA NA 95,501
27

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Table 7c—Acres by ownership, forest type, density, structure for Montana, west of the Continental Divide (continued)

Forest typea

Forest structureand density PP DF WL LP DLMC MLMC UMC S/F TL Other Total

Acres

 Two story 42,898 46,875 13,231 40,207 9,504 21,288 3,446 11,299 NA 6,433 195,181 Multistoried 58,366 269,277 6,518 6,452 18,953 70,451 7,208 53,213 NA NA 490,438 Total 120,241 335,753 45,374 93,464 37,294 110,059 12,377 72,272 NA 6,433 833,267 Density— Low 35,834 77,065 9,483 20,513 6,798 27,070 5,169 9,483 NA NA 191,415 Moderate 26,977 78,622 7,520 26,286 7,434 8,931 0 11,392 NA 6,433 173,595 High 57,430 180,066 28,371 46,665 23,062 74,058 7,208 51,397 NA NA 468,257 Total 120,241 335,753 45,374 93,464 37,294 110,059 12,377 72,272 NA 6,433 833,267NA = no plots recorded.a Forest type abbreviations definitions are PP = ponderosa pine, DF = Douglas-fir, WL = western larch, LP = lodgepole pine, DLMC = dry lower mixed conifer, MLMC = moist lower mixed conifer, UMC = upper mixed conifer, S/F = spruce/fir, TL = timberline.
28

 GENERAL TECHNICAL REPORT PNW-GTR-622 Table 7d—Acres by ownership, forest type, density, structure for Montana, east of the Continental Divide Forest type Forest structure and density a PP DF WL LP DLMC MLMC UMC S/F TL Other Total Acres Federal: Structure— No structure 4,320 NA NA NA NA NA NA NA 11,691 11,333 27,344 Scattered 180,863 93,522 NA 98,361 9,662 24,678 NA 115,480 47,458 40,370 610,394 One story 35,537 169,888 NA 1,225,155 NA NA 33,564 80,239 38,735 22,079 1,605,197 Two story 228,502 449,730 NA 680,550 12,286 37,017 48,963 298,378 93,401 77,461 1,926,288 Multistoried 259,759 1,064,069 NA 123,008 12,870 115,759 100,302 943,633 174,981 119,981 2,914,362 Total 708,981 1,777,209 NA 2,127,074 34,818 177,454 182,829 1,437,730 366,266 271,224 7,083,585 Density—

 Low 300,309 568,731 NA 632,730 9,662 109,629 64,151 446,331 162,353 107,156 2,401,052 Moderate 177,270 503,424 NA 721,618 6,049 42,516 63,483 520,616 52,166 81,389 2,168,531 High 231,402 705,054 NA 772,726 19,107 25,309 55,195 470,783 151,747 82,679 2,514,002 Total 708,981 1,777,209 NA 2,127,074 34,818 177,454 182,829 1,437,730 366,266 271,224 7,083,585Private: Structure— No structure 17,340 NA NA NA NA NA NA NA NA NA 17,340 Scattered 175,284 65,267 NA 35,950 NA NA 5,163 5,163 NA 18,172 304,999 One story 166,740 45,990 NA 128,017 14,324 11,309 5,499 17,319 NA 61,539 450,737 Two story 562,461 160,259 NA 77,279 16,305 11,370 9,385 19,796 NA 149,475 1,006,330 Multistoried 327,802 431,368 NA 40,940 6,554 NA 5,624 90,206 NA 117,174 1,019,668 Total 1,249,627 702,884 NA 282,186 37,183 22,679 25,671 132,484 NA 346,360 2,799,074 Density— Low 499,297 268,762 NA 174,907 5,499 22,679 10,662 44,208 NA 87,691 1,113,705 Moderate 397,958 221,231 NA 44,100 25,130 NA 0 30,664 NA 147,465 866,548 High 352,372 212,891 NA 63,179 6,554 NA 15,009 57,612 NA 111,204 818,821 Total 1,249,627 702,884 NA 282,186 37,183 22,679 25,671 132,484 NA 346,360 2,799,074Other: Structure— No structure NA NA NA NA NA NA NA NA NA NA NA Scattered 34,698 13,941 NA NA NA NA NA NA NA 11,957 60,596 One story 11,718 14,674 NA 41,507 NA NA NA 13,344 NA 27,768 109,011
29

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Table 7d—Acres by ownership, forest type, density, structure for Montana, east of the Continental Divide (continued)

Forest type

Forest structure and densitya PP DF WL LP DLMC MLMC UMC S/F TL Other Total

Acres

 Two story 107,526 13,532 NA 11,911 NA NA NA 18,769 NA 22,226 173,964 Multistoried 96,814 51,341 NA NA NA 5,716 5,716 17,148 6,195 32,048 214,978 Total 250,756 93,488 NA 53,418 NA 5,716 5,716 49,261 6,195 93,999 558,549 Density— Low 90,017 34,810 NA 24,442 NA NA NA 11,911 NA 44,278 205,458 Moderate 75,643 13,532 NA 11,401 NA NA 5,716 18,769 6,195 21,306 152,562 High 85,096 45,146 NA 17,575 NA 5,716 NA 18,581 NA 28,415 200,529 Total 250,756 93,488 NA 53,418 NA 5,716 5,716 49,261 6,195 93,999 558,549NA = no plots recorded.a Forest type abbreviations definitions are PP = ponderosa pine, DF = Douglas-fir, WL = western larch, LP = lodgepole pine, DLMC = dry lower mixed conifer, MLMC = moist lower mixed conifer, UMC = upper mixed conifer, S/F = spruce/fir, TL = timberline.
30

 GENERAL TECHNICAL REPORT PNW-GTR-622

Table 8—Acres by region, ownership, density, and structure

Ownership

Forest structure 

and density Federal Private Other Total

Acres

Montana:

 Structure—

 No structure 69,572 17,340 NA 86,912

 Scattered 1,227,501 591,299 112,743 1,931,543

 One story 3,019,169 864,129 204,512 4,087,810

 Two story 3,893,784 1,676,384 369,145 5,939,313

 Multistoried 6,596,090 2,113,142 705,416 9,414,648

 All 14,806,116 5,262,294 1,391,816 21,460,226

 Density—

 Low 5,196,387 1,960,276 396,873 7,553,536

 Moderate 5,036,769 1,504,040 326,157 6,866,966

 High 4,572,960 1,797,978 668,786 7,039,724

 All 14,806,116 5,262,294 1,391,816 21,460,226

 Structure/density— 

 Scattered, low 1,227,501 591,299 112,743 1,931,543

 Scattered, moderate NA NA NA NA

 Scattered, high NA NA NA NA

 One story, low 1,367,701 483,087 104,217 1,955,005

 One story, moderate 913,055 227,531 29,126 1,169,712

 One story, high 738,413 153,511 71,169 963,093

 Two story, low 1,600,834 621,928 119,442 2,342,204

 Two story, moderate 1,315,027 624,174 139,864 2,079,065

 Two story, high 977,923 430,282 109,839 1,518,044

 Multistoried, low 930,779 246,622 60,471 1,237,872

 Multistoried, moderate 2,808,687 652,335 157,167 3,618,189

 Multistoried, high 2,856,624 1,214,185 487,778 4,558,587

 All 14,736,544 5,244,954 1,391,816 21,373,314

West of the Continental Divide:

 Structure—

 No structure 42,228 NA NA 42,228

 Scattered 617,107 286,300 52,147 955,554

 One story 1,413,972 413,392 95,501 1,922,865

 Two story 1,967,496 670,054 195,181 2,832,731

 Multistoried 3,681,728 1,093,474 490,438 5,265,640

 All 7,722,531 2,463,220 833,267 11,019,018

 Density— 

 Low 2,795,335 846,571 191,415 3,833,321

 Moderate 2,868,238 637,492 173,595 3,679,325

 High 2,058,958 979,157 468,257 3,506,372

 All 7,722,531 2,463,220 833,267 11,019,018

 Structure/density—

 Scattered, low 617,107 286,300 52,147 955,554

 Scattered, moderate NA NA NA NA
31

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Table 8—Acres by region, ownership, density, and structure (continued)

Ownership

Forest structure 

and density Federal Private Other Total

Acres

 Scattered, high NA NA NA NA

 One story, low 715,889 214,949 37,190 968,028

 One story, moderate 399,388 95,788 23,441 518,617

 One story, high 298,695 102,655 34,870 436,220

 Two story, low 872,836 221,511 65,236 1,159,583

 Two story, moderate 704,505 204,921 56,830 966,256

 Two story, high 390,155 243,622 73,115 706,892

 Multistoried, low 547,275 123,811 36,842 707,928

 Multistoried, moderate 1,764,345 336,783 93,324 2,194,452

 Multistoried, high 1,370,108 632,880 360,272 2,363,260

 All 7,680,303 2,463,220 833,267 10,976,790

East of the Continental Divide:

 Structure—

 No structure 27,344 17,340 NA 44,684

 Scattered 610,394 304,999 60,596 975,989

 One story 1,605,197 450,737 109,011 2,164,945

 Two story 1,926,288 1,006,330 173,964 3,106,582

 Multistoried 2,914,362 1,019,668 214,978 4,149,008

 All 7,083,585 2,799,074 558,549 10,441,208

 Density—

 Low 2,401,052 1,113,705 205,458 3,720,215

 Moderate 2,168,531 866,548 152,562 3,187,641

 High 2,514,002 818,821 200,529 3,533,352

 All 7,083,585 2,799,074 558,549 10,441,208

 Structure/density—

 Scattered, low 610,394 304,999 60,596 975,989

 Scattered, moderate NA NA NA NA

 Scattered, high NA NA NA NA

 One story, low 651,812 268,138 67,027 986,977

 One story, moderate 513,667 131,743 5,685 651,095

 One story, high 439,718 50,856 36,299 526,873

 Two story, low 727,998 400,417 54,206 1,182,621

 Two story, moderate 610,522 419,253 83,034 1,112,809

 Two story, high 587,768 186,660 36,724 811,152

 Multistoried, low 383,504 122,811 23,629 529,944

 Multistoried, moderate 1,044,342 315,552 63,843 1,423,737

 Multistoried, high 1,486,516 581,305 127,506 2,195,327

 All 7,056,241 2,781,734 558,549 10,396,524

NA = no plots available.
32

 GENERAL TECHNICAL REPORT PNW-GTR-622

Table 9—Basal area ranges for low, moderate, and 

high density classes, by forest type, and geographic 

region within Montana

Basal area

Forest typea

and density Low Moderate High

Ft 2/acre

West of the Continental Divide:

 PP <50 50–100 >100

 DF <90 90–150 >150

 DLMC <80 80–130 >130

 WL <50 50–125 >125

 LP <100 100–160 >160

 MLMC <130 130–210 >210

 UMC <110 110–160 >160

 S/F <85 85–145 >145

 TL <50 50–80 >80

East of the Continental Divide:

 PP <40 40–75 >75

 DF <80 80–130 >130

 DLMC <60 60–130 >130

 WL NA NA NA

 LP <110 110–160 >160

 MLMC <130 130–210 >210

 UMC <100 100–160 >160

 S/F <100 100–160 >160

 TL <60 60–140 >140

NA = no plots recorded.

aForest type abbreviations definitions are PP = ponderosa pine, 

DF = Douglas-fir, WL = western larch, LP = lodgepole pine, 

DLMC = dry lower mixed conifer, MLMC = moist lower mixed 

conifer, UMC = upper mixed conifer, SF = spruce/fir, TL = 

timberline.
33

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Table 10—Average crowning index by region, ownership, density, and structure 

Ownership

Forest structure

and density Federal Private Other Total

Mph

Montana:

 Structure—

 No structure 51 63 — 53

 Scattered 69 66 71 68

 One story 32 40 38 34

 Two story 30 37 34 32

 Multistoried 25 25 24 25

 All 30 35 31 31

 Density—

 Low 45 52 54 47

 Moderate 27 34 29 29

 High 20 21 22 21

 All 30 35 31 31

 Structure/density—

 Scattered, low 69 66 71 68

 Scattered, moderate — — — —

 Scattered, high — — — —

 One story, low 42 48 54 45

 One story, moderate 27 37 25 29

 One story, high 20 19 28 20

 Two story, low 36 48 48 40

 Two story, moderate 28 36 30 31

 Two story, high 21 24 24 22

 Multistoried, low 33 33 41 33

 Multistoried, moderate 27 32 29 28

 Multistoried, high 20 20 21 20

 All 30 35 31 31

West of the Continental Divide:

 Structure—

 No structure 67 — — 67

 Scattered 75 61 75 71

 One story 38 39 39 38

 Two story 33 34 31 33

 Multistoried 28 24 24 26

 All 34 33 29 31

 Density—

 Low 49 51 54 50

 Moderate 29 33 28 30

 High 23 20 22 22

 All 34 33 29 31

 Structure/density—

 Scattered, low 75 61 75 71

 Scattered, moderate — — — —
34

 GENERAL TECHNICAL REPORT PNW-GTR-622

Table 10—Average crowning index by region, ownership, density, and 

structure (continued)

Ownership

Forest structure

and density Federal Private Other Total

Mph

 Scattered, high — — — —

 One story, low 48 46 64 49

 One story, moderate 31 41 25 32

 One story, high 22 21 29 23

 Two story, low 39 51 43 41

 Two story, moderate 30 32 28 30

 Two story, high 25 21 22 23

 Multistoried, low 36 34 41 36

 Multistoried, moderate 29 31 29 29

 Multistoried, high 23 19 21 22

 All 34 33 29 31

East of the Continental Divide:

 Structure—

 No structure 29 63 — 41

 Scattered 63 70 65 65

 One story 27 41 36 31

 Two story 26 39 41 31

 Multistoried 21 26 27 23

 All 26 37 37 29

 Density—

 Low 41 52 53 45

 Moderate 25 36 32 28

 High 18 22 24 19

 All 26 37 37 29

 Structure/density—

 Scattered, low 63 70 65 65

 Scattered, moderate — — — —

 Scattered, high — — — —

 One story, low 37 49 44 41

 One story, moderate 24 35 23 26

 One story, high 18 15 25 18

 Two story, low 33 46 58 38

 Two story, moderate 26 38 34 31

 Two story, high 19 28 31 21

 Multistoried, low 27 33 40 29

 Multistoried, moderate 24 32 31 27

 Multistoried, high 18 21 22 19

 All 26 37 37 29

— = insignificant data available.
35

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Table 11a—Average crowning index by region, forest type, density, and structure

Forest typea

Forest structureand density PP DF WL LP DLMC MLMC UMC S/F TL Other Total

Mph

Montana: Structure— No structure 62 63 NA NA NA 79 NA 42 25 24 53 Scattered 61 74 107 66 61 61 62 63 63 64 68 One story 57 51 48 25 33 45 31 34 27 45 34 Two story 40 34 37 24 33 38 31 27 24 41 32 Multistoried 30 25 32 27 29 25 27 22 17 25 25 Total 42 33 57 28 34 32 30 27 25 37 31 Density— Low 58 50 94 40 50 45 39 39 36 50 47 Moderate 38 28 47 25 34 28 30 24 18 39 29 High 27 20 32 19 23 21 22 19 14 20 21 Total 42 33 57 28 34 32 30 27 25 37 31West of the Continental Divide: Structure— No structure 76 63 NA NA NA 79 NA 42 NA NA 67 Scattered 56 78 107 49 72 50 53 72 56 NA 71 One story 82 55 48 27 38 45 31 35 37 NA 38 Two story 43 37 37 24 38 39 33 29 28 33 33 Multistoried 35 26 32 27 31 25 30 24 19 33 26 Total 45 35 57 28 37 32 32 30 29 33 33 Density— Low 62 53 94 39 51 46 41 43 36 43 50 Moderate 46 29 47 24 38 29 32 26 22 33 30 High 29 21 32 20 25 22 24 20 14 26 22 Total 45 35 57 28 37 32 32 30 29 33 33East of the Continental Divide: Structure— No structure 58 NA NA NA NA NA NA NA 25 24 41 Scattered 62 67 NA 85 44 89 101 48 67 64 65 One story 50 47 NA 24 16 49 31 32 21 45 31
36

 GENERAL TECHNICAL REPORT PNW-GTR-622 Table 11a—Average crowning index by region, forest type, density, and structure (continued) Forest typea Forest structure and density PP DF WL LP DLMC MLMC UMC S/F TL Other Total

Mph

 Two story 40 31 NA 24 24 34 23 24 20 42 31 Multistoried 28 23 NA 27 27 22 22 19 16 24 23 Total 41 30 NA 27 25 35 26 23 24 37 29 Density— Low 57 45 NA 40 44 44 35 32 36 51 45 Moderate 36 27 NA 25 19 18 26 22 15 40 28 High 26 19 NA 18 17 19 17 17 14 20 19 Total 41 30 NA 27 25 35 26 23 24 37 29NA = no plots recorded.aForest type abbreviations definitions are PP = ponderosa pine, DF = Douglas-fir, WL = western larch, LP = lodgepole pine, DLMC = dry lower mixed conifer, MLMC = moist lower mixed conifer, UMC = upper mixed conifer, SF = spruce/fir, TL = timberline.
37

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Table 11b—Average crowning index by ownership, forest type, density, and structure for Montana

Forest typea

Forest structureand density PP DF WL LP DLMC MLMC UMC S/F TL Other Total

Mph

Federal: Structure— No structure 60 64 NA NA NA 79 NA 42 25 24 51 Scattered 58 68 122 67 68 68 52 65 63 73 69 One story 68 54 52 25 NA 55 30 34 27 39 32 Two story 40 33 44 24 35 37 32 27 24 25 29 Multistoried 31 26 30 29 31 27 27 23 17 15 25 Total 43 33 67 27 38 35 29 27 26 29 30 Density— Low 56 49 106 38 59 45 36 39 36 47 45 Moderate 40 29 45 25 39 29 30 24 18 21 27 High 27 20 37 19 21 24 22 19 15 12 20 Total 43 33 67 27 38 35 29 27 26 29 30Private: Structure— No structure 63 NA NA NA NA NA NA NA NA NA 63 Scattered 63 77 73 63 50 47 69 52 NA 61 66 One story 51 42 48 29 34 35 29 32 NA 52 40 Two story 39 36 29 27 32 45 21 29 NA 50 37 Multistoried 28 24 NA 22 27 24 23 21 9 32 25 Total 41 33 49 32 33 32 34 27 9 43 35 Density— Low 57 50 63 44 45 46 55 43 NA 61 52 Moderate 38 29 63 30 22 25 28 25 NA 49 34 High 25 19 26 18 23 20 20 17 9 25 21 Total 41 33 49 32 33 32 34 27 9 43 35Other: Structure— No structure NA NA NA NA NA NA NA NA NA NA NA Scattered 63 104 72 72 0 30 NA 23 NA 38 70 One story 72 69 32 26 32 33 50 34 NA 36 38
38

 GENERAL TECHNICAL REPORT PNW-GTR-622 Table 11b—Average crowning index by ownership, forest type, density, and structure for Montana (continued) Forest typea Forest structure and density PP DF WL LP DLMC MLMC UMC S/F TL Other Total

Mph

 Two story 46 32 25 20 29 34 25 23 NA 43 34 Multistoried 32 24 33 16 27 20 32 18 14 27 24 Total 43 30 35 28 28 24 32 20 14 35 31 Density— Low 68 54 70 50 44 43 46 30 NA 41 54 Moderate 38 27 29 18 29 25 32 24 14 41 29 High 30 21 27 19 26 20 22 17 NA 20 22 Total 43 30 35 28 28 24 32 20 14 35 31NA = no plots recorded.aForest type abbreviations definitions are PP = ponderosa pine, DF = Douglas-fir, WL = western larch, LP = lodgepole pine, DLMC = dry lower mixed conifer, MLMC = moist lower mixed conifer, UMC = upper mixed conifer, SF = spruce/fir, TL = timberline.
39

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Table 11c—Average crowning index by ownership, forest type, density, and structure for Montana, west of the Continental Divide

Forest type a

Forest structureand density PP DF WL LP DLMC MLMC UMC S/F TL Other Total

Mph

Federal: Structure— No structure 76 64 NA NA NA 79 NA 42 NA NA 67 Scattered 56 73 122 45 116 54 52 75 56 NA 75 One story 107 60 52 27 NA 55 30 35 37 NA 38 Two story 45 39 44 25 41 37 35 30 28 NA 33 Multistoried 44 29 30 30 34 28 30 25 20 41 28 Total 52 37 67 27 42 35 32 31 29 41 34 Density— Low 61 53 106 37 75 46 39 43 36 41 49 Moderate 50 30 45 25 41 30 32 26 22 NA 29 High 36 23 37 21 25 25 25 21 15 NA 23 Total 52 37 67 27 42 35 32 31 29 41 34Private: Structure— No structure NA NA NA NA NA NA NA NA NA NA NA Scattered 60 78 73 38 50 47 53 54 NA NA 61 One story 59 45 48 29 43 28 17 50 NA NA 39 Two story 38 36 29 24 37 48 24 25 NA 35 34 Multistoried 30 23 NA NA 30 24 25 23 9 32 24 Total 41 33 49 28 38 31 30 31 9 33 33 Density— Low 57 53 63 40 45 48 45 47 NA 44 51 Moderate 44 29 63 30 31 25 28 23 NA 35 33 High 24 18 26 19 25 20 21 21 9 26 20 Total 41 33 49 28 38 31 30 31 9 33 33Other: Structure— No structure NA NA NA NA NA NA NA NA NA NA NA Scattered 27 117 72 72 NA 30 NA 23 NA NA 75
40

 GENERAL TECHNICAL REPORT PNW-GTR-622 Table 11c—Average crowning index by ownership, forest type, density, and structure for Montana, west of the Continental Divide (continued) Forest type a Forest structure and density PP DF WL LP DLMC MLMC UMC S/F TL Other Total

Mph

 One story 79 79 32 27 32 33 50 29 NA NA 39 Two story 48 32 25 18 29 34 25 24 NA 28 31 Multistoried 33 24 33 16 27 20 32 17 NA NA 24 Total 43 29 35 29 28 24 32 19 NA 28 29 Density— Low 74 53 70 57 44 43 46 25 NA NA 54 Moderate 41 27 29 17 29 25 NA 28 NA 28 28 High 32 20 27 19 26 20 22 17 NA NA 22 Total 43 29 35 29 28 24 32 19 NA 28 29NA = no plots recorded.aForest type abbreviations definitions are PP = ponderosa pine, DF = Douglas-fir, WL = western larch, LP = lodgepole pine, DLMC = dry lower mixed conifer, MLMC = moist lower mixed conifer, UMC = upper mixed conifer, SF = spruce/fir, TL = timberline.
41

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Table 11d—Average crowning index by ownership, forest type, density, and structure for Montana, east of the Continental Divide

Forest type a

Forest structure and density PP DF WL LP DLMC MLMC UMC S/F TL Other Total

Mph

Federal: Structure— No structure 44 NA NA NA NA NA NA NA 25 24 29 Scattered 58 60 NA 82 44 89 NA 48 67 73 63 One story 48 49 NA 24 NA NA 29 32 21 39 27 Two story 38 28 NA 23 17 36 24 23 20 25 26 Multistoried 27 23 NA 28 18 22 22 19 16 13 21 Total 40 28 NA 26 26 35 23 23 24 29 26 Density— Low 54 43 NA 39 44 45 28 31 36 47 41 Moderate 34 27 NA 25 22 18 25 22 15 21 25 High 25 18 NA 18 16 18 17 17 14 12 18 Total 40 28 NA 26 26 35 23 23 24 29 26Private: Structure— No structure 63 NA NA NA NA NA NA NA NA NA 63 Scattered 64 76 NA 98 NA NA 101 48 NA 61 70 One story 50 36 NA 28 16 49 41 23 NA 52 41 Two story 39 37 NA 31 28 29 17 38 NA 51 39 Multistoried 27 25 NA 22 17 0 16 20 NA 32 26 Total 41 33 NA 36 23 39 43 24 NA 44 37 Density— Low 57 46 NA 47 45 39 71 39 NA 64 52 Moderate 36 29 NA 29 18 NA NA 27 NA 50 36 High 25 20 NA 15 17 NA 16 14 NA 25 22 Total 41 33 NA 36 23 39 43 24 NA 44 37Other: Structure— No structure NA NA NA NA NA NA NA NA NA NA NA Scattered 69 78 NA NA NA NA NA NA NA 38 64
42

 GENERAL TECHNICAL REPORT PNW-GTR-622 Table 11d—Average crowning index by ownership, forest type, density, and structure for Montana, east of the Continental Divide (continued) Forest type a Forest structure and density PP DF WL LP DLMC MLMC UMC S/F TL Other Total

Mph

 One story 57 59 NA 24 NA NA NA 37 NA 36 36 Two story 44 32 NA 33 NA NA NA 22 NA 47 41 Multistoried 31 23 NA NA NA 21 32 20 NA 27 27 Total 43 37 NA 26 NA 21 32 25 NA 36 37 Density— Low 65 60 NA 33 NA NA NA 37 NA NA 53 Moderate 35 24 NA 22 NA NA 32 20 NA 44 32 High 27 25 NA 19 NA 21 NA 22 NA 20 24 Total 43 37 NA 26 NA 21 32 25 NA 36 37NA = no plots recorded.aForest type abbreviations definitions are PP = ponderosa pine, DF = Douglas-fir, WL = western larch, LP = lodgepole pine, DLMC = dry lower mixed conifer, MLMC = moist lower mixed conifer, UMC = upper mixed conifer, SF = spruce/fir, TL = timberline.
43

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Table 12—Average pre- and posttreatment crowning indexes by region, 

ownership, density, and structure: thin from below to 9 in treatment

Ownership

Forest structure

and density Federal Private Other Total

Mph

Montana:

 Structure—

 No structure — — — —

 Scattered — — — —

 One story 33/38 34/41 29/40 33/40

 Two story 31/37 32/43 37/49 32/40

 Multistoried 26/31 23/35 25/42 25/32

 All 27/33 26/37 27/33 27/34

 Density—

 Low 34/39 33/39 39/39 34/39

 Moderate 30/35 31/43 32/42 30/38

 High 22/28 21/33 23/30 22/30

 All 27/33 26/37 27/33 27/34

 Structure/density—

 Scattered, low — — — —

 Scattered, moderate — — — —

 Scattered, high — — — —

 One story, low 33/42 36/38 — 35/40

 One story, moderate 31/32 34/43 33/38 33/40

 One story, high — — 21/45 21/45

 Two story, low 38/39 33/37 38/38 36/38

 Two story, moderate 31/38 33/46 37/55 33/44

 Two story, high 24/32 29/39 36/44 27/36

 Multistoried, low 32/39 31/41 40/40 33/40

 Multistoried, moderate 29/34 29/41 29/33 29/35

 Multistoried, high 22/28 20/32 23/29 21/29

 All 27/33 26/37 27/33 27/34

West of the Continental Divide:

 Structure—

 No structure — — — —

 Scattered — — — —

 One story 31/31 34/34 29/40 32/35

 Two story 35/38 30/35 36/44 33/38

 Multistoried 28/30 22/25 25/27 26/28

 All 29/32 24/28 26/30 27/30

 Density—

 Low 37/37 33/33 39/39 36/36

 Moderate 31/34 30/34 31/36 31/35

 High 24/26 20/24 23/26 22/25

 All 29/32 24/28 26/30 27/30
44

 GENERAL TECHNICAL REPORT PNW-GTR-622

Table 12—Average pre- and posttreatment crowning indexes by region, ownership, density, and structure: thin from below to 9 in treatment (continued)

Ownership

Forest structure

and density Federal Private Other Total

Mph

 Structure/density—

 Scattered, low — — — —

 Scattered, moderate — — — —

 Scattered, high — — — —

 One story, low — 40/40 -/- 40/40

 One story, moderate 31/31 25/25 33/38 29/31

 One story, high — — 21/45 21/45

 Two story, low 38/38 32/32 38/38 36/36

 Two story, moderate 35/39 34/43 36/50 35/42

 Two story, high 28/32 26/32 27/44 27/32

 Multistoried, low 35/35 31/32 40/40 36/36

 Multistoried, moderate 30/33 29/32 29/32 30/33

 Multistoried, high 24/25 19/22 23/25 22/24

 All 29/32 24/28 26/30 27/30

East of the Continental Divide:

 Structure—

 No structure — — — —

 Scattered — — — —

 One story 33/41 35/45 — 34/43

 Two story 27/36 33/47 38/55 31/43

 Multistoried 23/33 24/45 23/49 23/37

 All 24/34 28/46 29/51 26/39

 Density—

 Low 31/42 32/47 — 31/44

 Moderate 27/36 32/48 36/58 30/42

 High 21/30 23/44 26/48 22/36

 All 24/34 28/46 29/51 26/39

 Structure/density—

 Scattered, low — — — —

 Scattered, moderate — — — —

 Scattered, high — — — —

 One story, low 33/42 30/37 — 32/40

 One story, moderate 33/35 36/47 — 36/46

 One story, high — — — —

 Two story, low 36/42 36/48 — 36/44

 Two story, moderate 28/38 33/48 37/59 31/45

 Two story, high 22/32 33/47 39/44 27/38

 Multistoried, low 28/43 30/51 — 29/45

 Multistoried, moderate 27/36 30/48 26/50 28/40

 Multistoried, high 20/30 21/43 23/49 21/35

 All 24/34 28/46 29/51 26/39

— = insignificant data available.
45

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Table 13—Average pre- and posttreatment crowning indexes by region, ownership, density, and structure: 50-percent BA removal treatment

Ownership

Forest structure

and density Federal Private Other Total 

Mph

Montana:

 Structure—

 No structure — — — —

 Scattered — — — —

 One story 31/76 31/38 23/45 30/46

 Two story 27/45 29/43 32/57 28/45

 Multistoried 25/53 22/46 24/56 24/51

 All 25/51 24/45 25/56 25/50

 Density—

 Low 32/38 28/33 34/47 31/38

 Moderate 29/53 29/45 30/53 29/51

 High 21/51 21/46 23/58 22/51

 All 25/51 24/45 25/56 25/50

 Structure/density—

 Scattered, low — — — —

 Scattered, moderate — — — —

 Scattered, high — — — —

 One story, low — 30/32 — 30/32

 One story, moderate 31/76 33/41 25/42 32/49

 One story, high — 19/21 21/48 20/35

 Two story, low 38/46 27/31 30/56 33/42

 Two story, moderate 29/45 31/42 32/51 30/45

 Two story, high 21/45 27/45 36/75 24/47

 Multistoried, low 29/34 29/35 37/43 30/35

 Multistoried, moderate 28/55 28/47 29/54 28/53

 Multistoried, high 21/52 20/46 22/57 21/51

 All 25/51 24/45 25/56 25/50

West of the Continental Divide:

 Structure—

 No structure — — — —

 Scattered — — — —

 One story 31/73 25/35 23/45 26/51

 Two story 31/52 25/40 30/55 29/48

 Multistoried 27/58 21/47 24/57 25/55

 All 28/57 22/45 24/56 26/54

 Density—

 Low 35/44 30/36 34/47 34/43

 Moderate 30/57 27/42 29/54 30/53

 High 24/60 19/47 22/58 22/55

 All 28/57 22/45 24/56 26/54
46

 GENERAL TECHNICAL REPORT PNW-GTR-622

Table 13—Average pre- and posttreatment crowning indexes by region, ownership, density, and structure: 50% BA removal treatment (continued)

Ownership

Forest structure

and density Federal Private Other Total 

Mph

 Structure/density—

 Scattered, low — — — —

 Scattered, moderate — — — —

 Scattered, high — — — —

 One story, low — — — —

 One story, moderate 31/73 25/35 25/42 27/51

 One story, high — — 21/48 21/48

 Two story, low 37/49 29/36 30/56 33/46

 Two story, moderate 33/51 28/40 31/53 31/48

 Two story, high 25/56 22/42 27/61 24/49

 Multistoried, low 33/41 32/37 37/43 34/41

 Multistoried, moderate 29/58 27/44 29/54 29/55

 Multistoried, high 24/60 19/48 22/58 22/56

 All 28/57 22/45 24/56 26/54

East of the Continental Divide:

 Structure—

 No structure — — — —

 Scattered — — — —

 One story 33/82 33/39 — 33/44

 Two story 23/40 31/44 35/59 27/43

 Multistoried 22/47 23/45 24/53 22/47

 All 22/46 26/44 28/55 24/46

 Density—

 Low 29/32 26/30 — 28/32

 Moderate 26/47 31/46 32/49 28/47

 High 19/46 23/44 26/58 21/46

 All 22/46 26/44 28/55 24/46

 Structure/density—

 Scattered, low — — — —

 Scattered, moderate — — — —

 Scattered, high — — — —

 One story, low — 30/32 — 30/32

 One story, moderate 33/82 35/43 — 35/48

 One story, high — 19/21 — 19/21

 Two story, low 39/43 23/24 — 34/37

 Two story, moderate 26/40 32/43 33/49 29/42

 Two story, high 19/40 31/48 39/79 24/46

 Multistoried, low 25/28 26/33 — 25/29

 Multistoried, moderate 26/50 28/50 26/48 27/50

 Multistoried, high 19/47 21/44 24/54 20/47

 All 22/46 26/44 28/55 24/46

— = insignificant data available.
47

A Strategic Assessment of Crown Fire Hazard in Montana: Potential Effectiveness and Costs of Hazard Reduction Treatments

Table 14—Average pre- and posttreatment crowning indexes by region, ownership, density, and structure: comprehensive treatment

Ownership

Forest structure 

and density Federal Private Other Total 

Mph

Montana:

 Structure—

 No structure — — — —

 Scattered — — — —

 One story 28/107 32/69 30/68 31/80

 Two story 29/83 30/74 32/93 30/81

 Multistoried 25/83 24/77 25/88 25/82

 All 26/84 26/76 26/89 26/82

 Density—

 Low 33/82 32/83 36/93 33/84

 Moderate 29/82 30/72 30/75 30/78

 High 22/86 21/77 23/94 22/84

 All 26/84 26/76 26/89 26/82

 Structure/density—

 Scattered, low — — — —

 Scattered, moderate — — — —

 Scattered, high — — — —

 One story, low 25/107 33/92 — 29/99

 One story, moderate 31/130 34/62 33/70 33/77

 One story, high 28/38 19/30 27/67 25/50

 Two story, low 36/86 33/82 34/104 35/88

 Two story, moderate 30/83 31/71 32/80 31/77

 Two story, high 22/81 27/76 39/103 25/81

 Multistoried, low 31/77 31/81 29/79 32/78

 Multistoried, moderate 29/81 29/76 29/71 29/79

 Multistoried, high 21/87 20/78 22/94 21/85

 All 26/84 26/76 26/89 26/82

West of the Continental Divide:

 Structure—

 No structure — — — —

 Scattered — — — —

 One story 27/137 31/94 29/73 29/103

 Two story 33/88 27/90 30/104 31/92

 Multistoried 28/88 23/85 25/90 26/88

 All 29/88 24/87 26/92 27/89

 Density—

 Low 35/89 33/95 36/93 35/91

 Moderate 30/89 28/87 29/78 30/87

 High 24/88 20/85 22/97 22/90

 All 29/88 24/87 26/92 27/89
48

 GENERAL TECHNICAL REPORT PNW-GTR-622

Table 14—Average pre- and posttreatment crowning indexes by region, ownership, density, and structure: comprehensive treatment (continued)

Ownership

Forest structure 

and density Federal Private Other Total 

Mph

 Structure/density—

 Scattered, low — — — —

 Scattered, moderate — — — —

 Scattered, high — — — —

 One story, low 23/148 34/113 — 30/127

 One story, moderate 31/125 25/67 33/70 29/87

 One story, high — — 21/80 21/80

 Two story, low 37/87 32/89 34/104 35/91

 Two story, moderate 33/93 28/92 28/96 31/93

 Two story, high 25/80 23/88 26/114 24/89

 Multistoried, low 33/86 34/94 39/79 35/86

 Multistoried, moderate 30/87 29/85 29/72 29/85

 Multistoried, high 24/89 19/85 22/96 22/90

 All 29/88 24/87 26/92 27/89

East of the Continental Divide:

 Structure—

 No structure — — — —

 Scattered — — — —

 One story 29/77 33/58 32/53 32/63

 Two story 26/80 32/64 35/74 29/72

 Multistoried 23/79 24/70 24/77 23/75

 All 24/79 27/67 29/75 25/74

 Density—

 Low 30/73 31/69 — 30/71

 Moderate 27/74 32/64 33/67 30/69

 High 20/84 23/70 27/81 21/79

 All 24/79 27/67 29/75 25/74

 Structure/density—

 Scattered, low — — — —

 Scattered, moderate — — — —

 Scattered, high — — — —

 One story, low 27/66 30/60 — 29/63

 One story, moderate 33/139 36/61 — 36/70

 One story, high 28/38 19/30 32/53 26/40

 Two story, low 34/85 34/74 — 34/81

 Two story, moderate 28/76 32/62 35/68 31/68

 Two story, high 20/82 30/66 36/89 25/76

 Multistoried, low 28/66 28/67 — 28/66

 Multistoried, moderate 27/71 30/68 28/62 28/69

 Multistoried, high 20/85 21/71 24/80 20/80

 All 24/79 27/67 29/75 25/74

— = insignificant data available.


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