£

Arapaho

National

Forest

Arapaho

National

Forest

Eagle Summit

Routt

National

Forest

Routt

National

Forest

Jackson Rand

Kremmling Parshall

Granby

Lake

Granby

Gilp

Empire

Georgetow

Silver

Plume

Fraser

Tabernash

Winter 

Park

East

Porta

Hot Sulphur Springs

Grand Lake

State

Bridge

Silverthorne Jackson

Larimer

QuickBird/ARCHER 

study area

70

34

40

Bureau of Land Management

Forest Service

National Park Service

Lakes

Railroads

Evergreen (deceased)

U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2008–3078

March 2009

Hazards Management in Grand County, Colorado—

Fire Fuels Characterization

Introduction

U.S. Geological Survey Rocky Mountain Geographic Science Center

USGS Fire Science Activities

The USGS Fire Science Initiative is designed to identify potential wildfire risks and related hazards and to 

mitigate their effects on people, property, and natural resources. The USGS Rocky Mountain Geographic 

Science Center (RMGSC) plays an integral role in the fire science demonstration project targeting Grand 

County, Colo., which uses remote sensing imagery, other geospatial data, and advanced classification 

techniques to produce inventories and assessments of the current state of the ecosystem. The data gathered—

extent of tree mortality and insect infestation, changes in fire fuels, susceptibility to post-fire effects, 

distribution of wildland-urban interface areas, etc.—will 

give much needed information to decisionmakers on the 

Federal, State, and local levels.

Figure 1. Map for Grand County, Colo., showing locations of Federal lands 

and deceased conifer populations. Red box shows location of study area 

for figures 3, 4, 6, and 7.

The threat of wildfires continues to put pressure on 

planning and mitigation efforts at Federal, State, and 

local levels—especially in the wildland-urban interface 

(WUI) areas. A key part of combating these hazards is the 

ability to inventory and assess fire fuels and associated risks, 

yet much of this information is either unknown or unavailable 

at scales adequate for decisionmaking. The U.S. Geological 

Survey (USGS) Fire Science Initiative is designed to identify 

potential wildfire risks and related hazards and to mitigate 

their effects on people, property, and natural resources. 

As a part of this initiative, the USGS Rocky Mountain 

Geographic Science Center (RMGSC) plays an integral 

role in the fire science demonstration project targeting 

Grand County, Colo. (fig. 1). The extensive lodgepole pine 

forests in Grand County are suffering widespread mortality 

from an unprecedented outbreak of Mountain Pine Beetle 

(Dendroctonus ponderosae), which is altering fire hazard 

and risk significantly. The county is an ideal choice for an 

integrated scientific approach to hazard assessment because 

it has a reservoir system that provides water to millions of 

users throughout the state; an expanding WUI; a variety of 

Federal, State, and privately owned land; and such at-risk 

values as the presence of threatened and endangered 

species. Potential post-wildfire effects include a risk of 

flooding and debris flows, damage to community and 

critical infrastructure, and the impairment of water quality 

and availability for human and animal use. 

The USGS RMGSC is using remote sensing imagery, 

other geospatial information, and advanced classification 

techniques to support fire science activities in Grand 

County. Specifically, these data and methods are being used 

to produce inventories and assessments of the current state 

of the ecosystem, including tree mortality as a result of insect 

infestation, susceptibility to erosion and other post-fire effects, 

the distribution of WUI areas, and other at-risk values. Products 

derived from this information will then be used to help address 

scientific questions pertaining to fire behavior, fire effects, and 

fuels management within forests from the individual stand to 

landscape scale.
Evergreen forest

Evergreen forest (deceased)

Deciduous forest

Barren lands

Developed high intensity

Developed medium intensity

Developed low intensity

Developed open space

Perennial ice/snow

Mixed forest

Shrub scrub

Grassland/herbaceous

Water

Pasture/hay

Cultivated crops

Woody wetlands

Emergent herbaceous 

wetlands

Vegetation Healthy

Vegetation Mortality

Bare/sparse 

vegetation

Dead coniferous 

vegetation

Deciduous/grassland 

vegetation

Living coniferous 

vegetation

In FY06, the USGS contributed to a pilot effort focused 

on high-risk wildland-urban interface (WUI) zones in Grand 

County. This effort conducted an initial pre-fire hazards 

inventory of the potential effects on life and property from 

post-fire flooding, landslides, and erosion within the Three 

Lakes watershed area in Grand County. The inventory 

included the geospatial analysis and classification from 

high-resolution 2005 NAIP (National Agricultural Imagery 

Program) natural color photography, medium-resolution 

Advanced Spaceborne Thermal Emission and Reflection 

Radiometer (ASTER) multispectral imagery, and elevation 

information. Potential hazard-event variables such as 

structures, topography, and deceased coniferous vegetation 

were identified and their spatial relationship quantified.

Field visits conducted within Grand County during the 

summer of 2007 generally verified the accuracy of the updated 

30-meter landcover product. However, they also underscored 

the need for high-resolution spatial, spectral, and temporal 

imagery as a means to characterize and monitor the rapidly 

changing landscape. To meet this need, the USGS RMGSC 

is currently using available high-resolution DigitalGlobe 

QuickBird II imagery (collected in August 2007) to develop 

classification systems that combine both pixel-based and 

Figure 4. Preliminary 

generalized classification 

delineating conifer morality; 

from DigitalGlobe QuickBird 

II imagery.

Figure 5. Topographic 

map of the Three Lakes 

area showing expanded 

WUI/community and dead 

coniferous vegetation at 5-m 

resolution, based on a recent 

topographic map (1:24,000) 

updated from a previous 

1950s version

Figure 3. DigitalGlobe QuickBird II multispectral natural color image, 2.4-meter resolution.

In FY07, a countywide 30-meter landcover inventory 

was produced using multi-year Landsat imagery, derived 

vegetation indices, National Land Cover Data (NLCD), and 

other ancillary geodata, employing a fusion of pixel-based 

and object-oriented classification techniques (fig. 2). This 

product (current to Fall 2006) illuminates the significant 

human and environmental changes that have occurred in 

Grand County during the past decade—not fully accounted 

for in other existing national landcover datasets—and 

includes a Deceased Conifer class, which illustrates the 

increasing scope of Mountain Pine Beetle infestation and 

concomitant vegetation mortality in the region.

Previous Accomplishments: Fiscal Years 2006–2007

object-oriented methodologies and that will be able to produce 

a fine-scale landcover inventory covering eastern Grand 

County (figs. 3, 4). Other sources of remote sensing imagery 

(such as ASTER and Landsat), derived landcover products, 

and geospatial data will also be used in this project. This 

product will support a host of fire science activities, including 

fire behavior studies and risk modeling, and is being used to 

produce updated 1:24,000-scale USGS topographic maps of 

eastern and central Grand County (fig. 5).

Figure 2. Updated Grand County, Colo., landcover dataset, derived from 1995–2006 Landsat imagery, NLCD, 

and other geodata. This product captures recent landcover change due to urbanization and identifies deceased 

coniferous vegetation (largely attributed to Mountain Pine Beetle infestation).

Present and Planned Future Activities
Bare/sparse vegetation

Dead conifer 

gray stage

Dead conifer 

red stage

Deciduous/grassland

Living coniferous 

Printed on recycled paper

Elizabeth Lile

USGS Rocky Mountain Geographic Science Center

ellile@usgs.gov (303) 202-4326

Jennifer Briggs

USGS Rocky Mountain Geographic Science Center

jsbriggs@usgs.gov (303) 202-4078

Christopher Cole

USGS Rocky Mountain Geographic Science Center; 

Parallel, Incorporated

cjcole@usgs.gov (303) 202-4134

Contact for additional information

Photograph by Craig Brunstien

Figure 7. Preliminary generalized classification delineating multi-stage conifer 

mortality; from CAP ARCHER imagery.

Figure 6. CAP ARCHER high-resolution hyperspectral 

image, 1-meter resolution.

The USGS RMGSC is also currently 

evaluating the utility of the Civil Air Patrol’s 

Airborne Real-time Cueing Hyperspectral 

Enhanced Reconnaissance sensor (CAP 

ARCHER) for forest assessment and 

environmental monitoring applications within 

Grand County. The CAP ARCHER imagery 

was acquired for an area of interest within 

the Three Lakes WUI in August 2007. The 

ARCHER system boasts 1-meter spatial 

resolution across 52 spectral bands spanning 

the visible green to near infrared spectrum. 

Preliminary classification results indicate that 

ARCHER may facilitate fine-scale delineation 

of deceased pine at multiple stages of beetle 

attack and foliar senescence (that is, red and 

gray stages); it may also enable the detection 

of insect-stressed vegetation (figs. 6, 7). The 

ARCHER sensor may prove to be a new tool 

for tree-level landcover mapping and fire fuels 

analysis and may contribute to the scientific 

understanding of forest structure and health.

The USGS RMGSC is using remote 

sensing imagery and other geospatial 

information to develop products to support fire 

science efforts in Grand County, Colo. The 

best available information, including mediumand high-resolution imagery and geospatial 

data, is being used to evaluate landscape 

change and related potential wildfire effects 

on the Three Lakes WUI and associated 

watersheds. The spatial and temporal aspects 

of hazards and the potential for interaction 

among hazards are also being evaluated by 

USGS scientists in other disciplines, who will 

use RMGSC’s results to evaluate the effects 

of tree mortality and potential wildfires on 

several critical processes and ecosystem 

services: water quality and quantity, aquatic 

habitat and native fish populations, erosion 

and debris flow potential, and social and 

economic values.