89

Environmental 

Consequences

T

h e c e q r e g u l a t i o n s that implement the procedural 

provisions of the National Environmental Policy Act

(40 Code of Federal Regulations [CFR] 1502) require 

that environmental documents discuss the environmental 

impacts (both adverse and beneficial) of a proposed federal 

action, feasible alternatives to that action, and any adverse 

environmental effects that cannot be avoided if a proposed 

action is implemented. In this case, the proposed federal action 

would be the adoption of a general management plan for the 

Ice Age Complex at Cross Plains. 

Chapter Four

The National Park Service 

(NPS) Director’s Order 

12: Conservation Planning, 

Environmental Impact Analysis, 

and Decisionmaking and its 

accompanying Handbook 

require that impacts on park 

resources be analyzed in terms 

of their context, duration, and 

intensity. It is crucial for the 

public and decision makers to 

understand the implications 

of those impacts in the short 

and long term, cumulatively, 

and within context, based 

on an understanding and 

interpretation by resource 

professionals and specialists. 

This chapter analyzes the 

environmental impacts of 

implementing any one of the 

five alternatives proposed 

in this document. For each 

impact topic, there is a 

description of the methods 

and assumptions used for the 

impact analysis. The impact 

analysis discussions are 

organized by resource topic, 

followed by each alternative 

under each topic. Table 7 in 

chapter 2 provides a summary 

of the impacts. 

Bird tracks in 

the snow.

FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT
90 ICE AGE COMPLEX AT CROSS PLAINS

CHAPTER FOUR ENVIRONMENTAL CONSEQUENCES

Definitions for 

Evaluating Effects

The impact discussion for each resource topic 

describes the types of impacts (same as the 

term “effects”) that would result from taking 

no action or implementing any of the four 

action alternatives; those effects are described 

according to the definitions shown below.

Types of Effects

Beneficial Effects. These effects would result 

in a change that moves a resource toward its 

desired condition. 

Adverse Effects. These effects would result in 

a change that moves a resource away from its 

desired condition. 

Direct Effects. These effects would be caused 

by the action and occur at the same place and 

time as the action. 

Indirect Effects. These effects would also be caused 

by the action, would occur later in time, and 

would be further removed in distance but would 

still be reasonably foreseeable; or the response 

of the target resource would be triggered by the 

reaction of another resource to the action.

Cumulative Effects. These effects would result 

from the incremental impact of the action 

when added to other past, present, and 

reasonably foreseeable future actions.

Duration of Effects

Short-term Effects. These effects would be 

temporary, lasting a year or less, such as effects 

associated with construction.

Long-term Effects. These effects would last 

more than one year and could be permanent.

Intensity of Effects

“Intensity” refers to the severity of effects or 

the degree to which an action would adversely 

or beneficially affect a resource. The intensity 

definitions are presented in each resource 

section because they vary by resource topic.

Past, Present, and Reasonably 

Foreseeable Future Actions 

On or In the Vicinity of the 

Ice Age Complex

Cumulative actions are those that have additive 

impacts on a particular environmental resource. 

It is irrelevant who takes these actions (that is, 

they are not confined to NPS or even federal 

activities), or whether they took place in the 

past, are taking place in the present, or could 

take place in the reasonably foreseeable future. 

The Council on Environmental Quality (CEQ) 

interprets the National Environmental Policy 

Act (NEPA) and CEQ’s NEPA regulations on 

cumulative effects as requiring analysis and a 

concise description of the identifiable present 

effects of past actions to the extent they are 

relevant and useful in analyzing whether the 

reasonably foreseeable effects of the agency’s 

proposed action and alternatives could have a 

continuing, additive, and significant relationship 

to those effects. 

The current or reasonably foreseeable future 

actions considered for the purpose of assessing 

cumulative effects in this chapter include 

agricultural activities 

construction of a bike path by the town 

of Cross Plains along U.S. Highway 14, 

with a possible decision by NPS staff to 

provide a route through the complex 

to connect the city of Middleton to the 

town of Cross Plains

new residential development

snowmobiling outside the complex 

boundaries

events, such as the Ford Ironman 

(whose course currently runs through 

the complex) 

road maintenance activities such as 

salting for ice melt, which results in 

runoff and impacts on water quality 
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT 91

Chapter Four Environmental Consequences

Soil Resources

Analysis Methodology

This impact analysis is based on the knowledge 

of the soil types at the complex and also how 

development and other land use changes 

would impact soils. Soils could be adversely 

impacted by human activity in two ways: either 

by increased activity, which would cause soil 

compaction along trails, parking areas, and 

other developed areas; or by disturbance of 

vegetation cover and forest duff on the soil 

surface, which could lead to soil erosion. 

Disturbance of vegetation is a potential 

problem, particularly on steep slopes in the 

Cross Plains gorge and along the edge of Black 

Earth Creek valley. 

“Intensity” refers to the severity of effects 

or the degree to which an action would 

adversely or beneficially affect a resource. 

The intensity levels used to evaluate impacts 

on soils are listed below. The intensity levels 

below apply only to adverse impacts. When 

the term “beneficial” is used in this analysis 

to describe impacts, those impacts would 

always be negligible and long term. In this case 

“beneficial” refers to the avoidance of loss 

of productive soil as opposed to increasing 

the amount of soil. The formation of soil is 

a complex process that can take more than a 

thousand years to produce just a single inch 

of soil. During the process rocks, minerals, 

and other parent materials are weathered. 

The resulting soil varies, depending on the 

degree of weathering (a function of climate); 

the duration of weathering (a function of 

time); the site-specific biological activity; and 

landscape position (a function of topography). 

Because of this long, natural process, the 

activities that would take place under any of 

the alternatives would either adversely affect 

soil in a way that would take generations to 

reverse or avoid adverse impacts that would 

otherwise be expected (called “beneficial 

impacts” in this analysis). 

Negligible. Soil compaction or vegetation 

disturbance that creates erosion might occur, 

but the change would be so small that it would 

not be measurable. 

Minor. Soil compaction or vegetation 

disturbance that creates erosion would occur 

and would be measurable but would have little 

consequence.

Moderate. Soil compaction or vegetation 

disturbance that creates erosion would occur 

and would be measurable, resulting in smallscale consequences that could be remedied.

Major. Soil compaction or vegetation 

disturbance that creates erosion would be 

substantial at certain locations and would not 

be easily remedied.

Alternative 1: No Action, Continuation 

of Current Management — Direct and 

Indirect Impacts on Soils

It is expected that alternative 1 would have 

some beneficial impacts on soils due to 

conversion of farm land to prairie. Some 

soils would be removed from cultivation and 

converted to their presettlement condition 

(mostly prairie). The ability to farm the prime 

soils today would be curtailed, and the soils 

would be retained for the future because the 

deep roots of prairie grasses are very effective 

at holding soil. 

The intensity of impacts on soils caused by 

trail construction would be limited to minor 

ground disturbance within the narrow tread 

corridor. The potential impacts on soils from 

constructing and using the trail would be 

mitigated to a negligible level with proper 

layout of the trail on the landscape (for 

example, on slopes less than 10%), erosion 

control techniques, planking or bridges, 

and trail monitoring. The proper erosioncontrol techniques that would be employed, 

as necessary, include sidehill construction, 

waterbars, and drainage dips. Soils that are 

particularly unsuitable, such as in poorly 
92 ICE AGE COMPLEX AT CROSS PLAINS

CHAPTER FOUR ENVIRONMENTAL CONSEQUENCES

drained areas, would be avoided. If the trail 

must cross a wet area, planking or bridges 

would minimize the negative impacts from this 

crossing. Volunteer trail maintainers would 

monitor trails to help identify any cumulative 

erosion problems so that appropriate erosioncontrol actions could be taken. The National 

Park Services, in conjunction with the 

Wisconsin Department of Natural Resources 

and the Ice Age Park and Trail Foundation, 

has developed a handbook on trail design, 

construction, and maintenance for the Ice Age 

National Scenic Trail. This handbook is used 

by all volunteer trail builders. The Ice Age Trail 

Alliance also has a “mobile skills crew” that 

trains volunteers to build sustainable trails 

with minimal environmental impacts. 

The present land use in the Ice Age Complex 

would continue to be a mix of row crop 

agriculture (corn and soybeans), forest land, 

and oak savanna. When agricultural fields are 

plowed, soil surface is disturbed, and there 

is wind erosion of silt particles and organic 

particles off those surfaces. There is also water 

erosion from the fields. There is similar land 

use throughout Dane County. The impacts 

of agriculture on erosion would be minor to 

moderate, depending on numerous factors, 

such as the amount of tillage and use of grass 

strips to limit erosion in critical spots.

The Ice Age National Scenic Trail would 

still be built under this alternative but other 

trails would not. Over time, unauthorized 

trails (paths created by visitors, rather than 

formally planned and constructed) would 

proliferate. Since there would be no plan 

providing comprehensive guidance on 

resource management, resources would likely 

be managed inconsistently. There is currently 

minimal impact from erosion and compaction 

in forest and oak savanna areas under present 

use, with the exception of the Cross Plains 

gorge and the moraine between the Cross 

Plains gorge and Cleveland Road. There is 

currently minor impact on the trail on the 

moraine; impact would remain minor if usage 

is limited to hiking. If there is no enforcement 

of restrictions on the use of this trail, and 

if use by horseback riders were to increase, 

there would be a moderate impact due to 

compaction. There is compaction at small 

parking areas off Mineral Point Road and 

Timber Lane, but this land has already been 

disturbed, and there would be minimal 

further compaction.

The steep walls of Cross Plains gorge attract 

visitors, and human activity has the potential 

to damage both forest duff cover and soils, 

which could lead to substantial erosion 

problems. While the steep walls of Black Earth 

Creek valley are also susceptible to erosion if 

vegetation is disturbed, under present use, the 

slopes are not visited as much as those of the 

Cross Plains gorge. As time passes, however, 

this site could become better known, and 

residential development might increase in 

the area. If increased use is not accompanied 

by measures to protect these areas, such as a 

designed and delineated trail, damage to the 

steep walls would be expected. There could 

potentially be moderate to major erosion 

impacts if uncontrolled human activity in the 

vicinity of Cross Plains gorge and Black Earth 

Creek valley increased. 

Alternative 2: Ecological Restoration 

Emphasis — Direct and Indirect 

Impacts on Soils 

Alternative 2 would have the same beneficial 

impacts on soils as expressed in the first 

paragraph under alternative 1. 

This alternative would contribute to increased 

trail usage, compared to alternative 1 (no 

action), and would therefore likely have a 

minor impact on soils from compaction. 

There would be moderate impact on soils 

from compaction in parking areas, but these 

would not be large areas and would likely be 

in the same places as in alternative 1. Paving 

the parking lots would contribute to increased 

runoff and would require proper management.
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT 93

Chapter Four Environmental Consequences

The installation of trails near, but not in, 

Cross Plains gorge would minimize impact 

on the walls of the gorge. Erosion impacts in 

the gorge itself would be negligible because 

the public would be directed (with trail design 

and signage) to stay off the walls of the gorge. 

Because the complex would be managed from 

an off-site location, there would be little ability 

to enforce this direction. If the public does not 

comply with the direction to stay off the gorge 

walls, there could be moderate adverse impacts 

on soil and the forest duff covering the wall 

until the park has the capacity to stop this from 

happening, given the minimal off-site staff.

Alternative 3: Interpretation and 

Education Emphasis — Direct and Indirect 

Impacts on Soils

Alternative 3 would have the same beneficial 

impacts on soils as expressed in the first 

paragraph under alternative 1.

The construction of buildings and a surfaced 

trail to Cross Plains gorge could potentially 

have a temporary moderate adverse impact 

on soils from erosion and compaction in areas 

subject to construction. Once construction is 

completed, there would still be some potential 

for minor compaction from visitor use, but 

the minor impacts would be confined to areas 

around buildings and parking lots. The onsite interpretation and maintenance facilities 

would potentially focus some visitor foot 

traffic to the interpretation building and away 

from the steep walls of Cross Plains gorge and 

steep slopes at the edge of Black Earth Creek 

valley. This would reduce the potential for soil 

compaction and erosion from uncontrolled 

human activity, resulting in minor to moderate 

beneficial impacts on those areas. 

Alternative 4: Outdoor Recreation 

Emphasis — Direct and Indirect 

Impacts on Soils

Alternative 4 would have the same beneficial 

impacts on soils as expressed in the first 

paragraph under alternative 1.

The construction of buildings and a surfaced 

trail to Cross Plains gorge, as well as a bridge 

across the gorge, could potentially have a 

temporary moderate adverse impact on soils 

from erosion and compaction in areas subject 

to construction. There would be additional 

trails across the site that would create 

moderate compaction in the vicinity of the 

trail. Once the landscape is stabilized following 

construction, compaction from visitor foot 

traffic would be confined to the areas around 

buildings and parking lots, which could 

potentially result in minor adverse impacts. 

The addition of a bicycle trail from the 

visitor center to a parking lot north of Black 

Earth Creek would increase visitor activity 

in a sensitive area, resulting in a moderate 

adverse impact on the steep slopes facing 

the creek, especially along the trail. The onsite interpretation and maintenance facilities 

would potentially focus some visitor foot 

traffic to the interpretation building and away 

from the steep walls of Cross Plains gorge and 

steep slopes at the edge of Black Earth Creek 

valley. This would reduce the potential for soil 

compaction and erosion from uncontrolled 

human activity, resulting in minor to moderate 

beneficial impacts on those areas. 

Alternative 5: Preferred Alternative — 

Direct and Indirect Impacts on Soils

Alternative 5 would have the same beneficial 

impacts on soils as expressed in the first 

paragraph under alternative 1.

The construction of buildings and a surfaced 

trail to Cross Plains gorge could potentially 

have a moderate adverse impact on soils from 

erosion and compaction during construction. 

There would be additional trails across the 

site that would create moderate compaction in 

the vicinity of the trail. Once the landscape is 

stabilized following construction, compaction 

from visitor foot traffic would be confined to 

the areas around buildings and parking lots, 

which could potentially result in minor adverse 

impacts. The on-site interpretation and 
94 ICE AGE COMPLEX AT CROSS PLAINS

CHAPTER FOUR ENVIRONMENTAL CONSEQUENCES

maintenance facilities would potentially focus 

some visitor foot traffic to the interpretation 

building and away from the steep walls of 

Cross Plains gorge and steep slopes at the edge 

of Black Earth Creek valley. This would reduce 

the potential for soil compaction and erosion 

from uncontrolled human activity, resulting in 

minor to moderate beneficial impacts on 

those areas.

All Alternatives — Cumulative Impacts 

on Soils

The soils in much of the Ice Age Complex 

have likely been altered by past activities 

(such as agricultural practices). Some soils on 

lands adjacent to the complex could be lost 

or modified in the future if the town of Cross 

Plains builds a bike path along U.S. Highway 

14. The decision could be made by NPS staff 

to provide a route through the complex to 

connect the city of Middleton to the town of 

Cross Plains. These actions would result in 

cumulative effects on soils in localized areas.

Alternative 1: No Action, Continuation of 

Current Management. If impacts of the abovedescribed developments were added to the 

continuing minor to major adverse impacts 

under the no-action alternative, there would 

be a long-term negligible to major adverse 

cumulative impact on area soils. 

Alternative 2: Ecological Restoration Emphasis.

If impacts of present or future actions were 

added to the negligible to moderate adverse 

impacts under alternative 2, there would 

be a long-term minor to moderate adverse 

cumulative impact on area soils. 

Alternative 3: Interpretation and Education 

Emphasis; Alternative 4: Outdoor Recreation 

Emphasis; and Alternative 5: Preferred 

Alternative. If impacts of present and future 

actions were added to the minor to moderate 

adverse impacts under alternatives 3, 4, and 5, 

there would be long-term minor to moderate 

adverse cumulative impacts on area soils. 

Water Quality

Groundwater could potentially be 

contaminated through openings in dolomite 

rock. Of particular concern is the area of 

Shoveler Sink and Coyle Pond, which both 

sit on the surface water divide between Black 

Earth Creek, Sugar River, and Yahara River 

basins. The sink and pond are closed basins 

with no surface water outflow. The closed 

basins collect water from adjoining hillslopes 

and are areas of concentrated groundwater 

recharge. Normally, this takes place slowly 

through sediment at the bottom of the ponds. 

At times of high water levels, they drain 

into a sinkhole in fractured limestone, thus 

potentially introducing contaminants into 

the groundwater system. The sinkhole allows 

surface water to rapidly enter the groundwater 

system without the benefit of “filtering” out 

contaminants. There is possibly a small cave 

system somewhere beneath this part of 

the complex.

Analysis Methodology

This impact analysis is based on knowledge 

of water resources and flow patterns at the 

Ice Age Complex. The analysis focuses on 

groundwater impacts because, as described 

in chapter 3, nearly all of the complex is a 

groundwater recharge area, meaning surface 

water goes into the groundwater system. All 

impacts on groundwater also apply to surface 

water (such as Coyle Pond, Shoveler Sink, and 

Black Earth Creek). 

The intensity levels used to evaluate impacts 

on water quality are provided below. 

Negligible. Changes would be either barely 

detectable or would have effects that would be 

considered slight and localized. 

Minor. An action would have measurable 

effects on water quality in a localized area. 

Moderate. An action would have clearly 

detectable effects on water quality and would 

potentially affect natural ecological processes. 
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT 95

Chapter Four Environmental Consequences

Major. An action would have substantial effects 

on water quality and would potentially affect 

natural ecological processes. 

Alternative 1: No Action, Continuation of 

Current Management — Direct and Indirect 

Impacts on Water Quality

At this time, the small basin that collects surface 

water that flows into Coyle Pond is partly used 

for row crops. Whatever tillage techniques 

are used, the application of herbicides and 

fertilizer has the potential to contaminate 

groundwater by passing through the limestone 

beneath the sinkhole. At this time land around 

Shoveler Sink is not in intensive agriculture, and 

chemicals are not being applied to the fields, 

so there is currently negligible adverse impact 

from agricultural runoff. 

Alternative 2: Ecological Restoration 

Emphasis — Direct and Indirect 

Impacts on Water Quality

Any adverse impact on groundwater would 

be negligible because the small basin that 

collects surface water flowing into Coyle 

Pond would be put back into presettlement 

vegetation under this alternative. In fact, over 

time, agricultural chemicals would not enter 

the groundwater system through the sink, so 

this would likely have a beneficial effect on 

groundwater quality, but the amount of this 

effect cannot be quantified. 

Alternative 3: Interpretation and 

Education Emphasis; 

Alternative 4: Outdoor Recreation 

Emphasis; and 

Alternative 5: Preferred Alternative — 

Direct and Indirect Impacts on Water Quality

These alternatives envision an indoor facility 

with modern amenities (such as indoor 

plumbing) for visitors, so there would be a 

need for a new well and septic system near the 

core area of the property. These would be built 

to appropriate codes and would therefore have 

a negligible impact on groundwater. 

Cumulative Impacts on Water Quality

Water quality in much of the Ice Age Complex 

is generally in good condition and has not 

been greatly altered by past activities (such as 

agricultural practices). 

The small basin that collects surface water 

that flows into the Coyle Pond is partly 

used for row crops at this time. None of the 

alternatives would restrict land use in this area, 

so it could remain in intensive agriculture. 

Whatever tillage techniques are used, the 

application of herbicides and fertilizers could 

result in a moderate potential to contaminate 

groundwater by passing through the 

limestone beneath the sinkhole. Land around 

Shoveler Sink is not in intensive agriculture, 

and chemicals are not being applied to the 

fields, so there would be minimal impacts 

from agricultural runoff. If land use were 

to remain the same, then any impacts from 

the alternatives, combined with agricultural 

activities, would potentially result in negligible 

cumulative impacts. Impacts on water quality 

from road maintenance activities, such as road 

salt runoff, would continue. 

Water quality could be adversely affected by 

potential future new development on adjacent 

lands. The Ice Age National Scenic Trail would 

eventually be developed through the complex. 

The possible future actions outside the complex 

boundary could affect water quality in Black 

Earth Creek and possibly Shoveler Sink. 

Alternative 1: No Action, Continuation of Current 

Management. If potential impacts from the 

above activities were added to the continuing 

negligible adverse impacts under the noaction alternative, there would be long-term 

negligible adverse cumulative impacts on water 

quality, depending on the type and quantity 

of pollutants that enter the waters within the 

complex. However, the level of impacts added 

by the no-action alternative would be relatively 

small compared to the impact from pollutants 

being added from actions outside the 

complex boundary. 
96 ICE AGE COMPLEX AT CROSS PLAINS

CHAPTER FOUR ENVIRONMENTAL CONSEQUENCES

Alternative 2: Ecological Restoration Emphasis. If 

impacts from the above activities were added 

to the negligible adverse impacts on water 

quality under alternative 2 (negligible because 

of the conversion of agricultural lands back 

to presettlement vegetation), there would 

be long-term negligible to moderate adverse 

cumulative impacts on the complex’s water 

quality, depending on the type and quantity 

of pollutants that might enter the waters in 

the complex. However, the level of impacts 

added by alternative 2 would be relatively 

small compared to the impact from pollutants 

that could potentially be added from actions 

outside the complex boundary. 

Alternative 3: Interpretation and Education 

Emphasis; Alternative 4: Outdoor Recreation 

Emphasis; and Alternative 5: Preferred 

Alternative. If impacts from future actions 

were added to the negligible to moderate 

impacts under alternatives 3, 4, and 5 (due to 

no restrictions on land use), there would be 

negligible to moderate adverse cumulative 

impacts on water quality, depending on the 

type and quantity of pollutants that could 

potentially enter the waters within the 

complex. However, the level of impacts added 

by each of the three alternatives would be 

relatively small compared to the impact from 

pollutants that could potentially be added 

from actions outside the complex boundary. 

Soundscapes

Analysis Methodology

As mentioned in chapter 3, there is abundant 

natural quiet in areas of the complex furthest 

from the roads (U.S. Highway 14, Timber 

Lane, Old Sauk Pass, and Mineral Point 

Road) that surround and traverse it. One of 

the fundamental resources of the complex 

is “the opportunity for people, particularly 

those in the adjacent urban area, to experience 

immersion into a large, natural landscape.” 

Therefore, in this analysis, activities in the 

alternatives that would remove or lessen 

unnatural sounds would be beneficial to the 

soundscape, and activities that would add or 

increase unnatural sounds would result in 

adverse impacts. Note that traffic noise on U.S. 

Highway 14, Timber Lane, and Mineral Point 

Road would likely continue to grow regardless 

of the future direction of the complex. The 

volume of traffic on these roads is related 

much more strongly to land use patterns in the 

region (suburban and exurban development) 

than to land use in the complex. The analysis 

below refers only to the soundscape impacts 

that might result from the actions that the park 

would take under each alternative. 

The intensity levels used to evaluate impacts 

on the soundscape are provided below. 

Negligible. There would be no audible impacts 

on the soundscape. Impacts would be of short 

duration and well within natural fluctuations. 

Noise would not affect appropriate transmission 

of natural sounds. 

Minor. Impacts on the soundscape would be 

slight but audible. Impacts would likely not be 

outside the range of natural variability. Noise 

would be expected to have short-term impacts 

on the soundscape or short-term impacts on 

appropriate transmission of natural sounds.

Moderate. Impacts on the soundscape would 

be clearly audible. Impacts would sometimes 

be outside the range of natural variability. 

Noise would not be expected to have longterm impacts on the soundscape or any longterm impacts on appropriate transmission of 

natural sounds.

Major. Impacts on the soundscape would be 

clearly audible and would be well outside the 

range of natural variability. Noise would have 

long-term impacts on the soundscape or longterm impacts on appropriate transmission of 

natural sounds.
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT 97

Chapter Four Environmental Consequences

Alternative 1: No Action Alternative, 

Continuation of Current Management — 

Direct and Indirect Impacts 

on the Soundscape

Due to minimal development of visitor 

amenities, this alternative would be expected 

to have the lowest level of visitation out of the 

five alternatives and therefore the least visitorcreated noise. It seems likely that, overall, there 

would be negligible impacts on the soundscape. 

Alternative 2: Ecological Restoration 

Emphasis — Direct and Indirect Impacts 

on the Soundscape

This alternative would increase trail usage 

over the no-action alternative, which could 

potentially result in more visitor-generated 

noise. In the short term, there would be noise 

generated from the removal of the structures 

at the core of the property, but those moderate 

adverse impacts on the soundscape would be 

temporary. Over the long term, most of the 

complex would be managed to allow visitors “a 

direct sensory experience of natural resources” 

(refer to table 2 in chapter 2 for the natural 

experience management area description 

for desired visitor experience), indicating 

negligible impacts on the soundscape. 

Alternative 3: Interpretation and 

Education Emphasis — Direct and Indirect 

Impacts on the Soundscape

Alternative 3 would result in a considerable 

increase in visitation compared to the noaction alternative, which could lead to more 

visitor-generated noise. In the short term, 

there would be noise generated from the 

renovation of the structures at the core of the 

property, but these moderate adverse impacts 

on the soundscape would be temporary. Over 

the long term, most of the complex would be 

managed for landscape interpretation, under 

which the management prescription (refer 

to table 2 in chapter 2) for visitor experience 

would concentrate on offering views of the 

results of glaciation instead of offering direct 

sensory experience of natural resources, as the 

natural experience management area would, 

indicating the potential for minor adverse 

soundscape impacts. 

Alternative 4: Outdoor Recreation 

Emphasis — Direct and Indirect Impacts 

on the Soundscape

Alternative 4 could result in a considerable 

increase in visitation, which would lead to 

considerably more visitor-generated noise. 

There would be noise generated from the 

construction of structures at the core of the 

property, but these moderate adverse impacts 

on the soundscape would be temporary. 

The bike path across the complex could 

generate more visitors and more noise per 

visitor than the hiking trails under the other 

alternatives. Most of the complex would be 

managed for landscape interpretation or 

for an expanded recreational experience, 

under which the management prescription 

for visitor experience would concentrate on 

offering views of the results of glaciation and 

the opportunity for low-impact recreation. 

However, there would also be a large natural 

experience area at the corner of two of the 

major roads on the edge of the complex. 

Overall, adverse impacts on the soundscape 

would be minor.

Alternative 5: Preferred Alternative — 

Direct and Indirect Impacts 

on the Soundscape

Impacts on the soundscape under the 

preferred alternative would be very similar to 

alternative 4, albeit slightly less because there 

would not be a bike path across the complex 

under this alternative. Overall, adverse impacts 

on the soundscape would be negligible 

to minor.
98 ICE AGE COMPLEX AT CROSS PLAINS

CHAPTER FOUR ENVIRONMENTAL CONSEQUENCES

Cumulative Impacts on the Soundscape

Noise from outside the complex has minimally 

affected the complex’s soundscape in the past 

and would continue to affect the soundscape, 

but perhaps at greater levels as the population 

continues to grow and traffic increases on 

roads adjacent to and through the complex.

Depending on the location in the complex, 

common human-caused sounds (such as 

vehicles on roads, maintenance activities, and 

agricultural activities) would continue to be 

heard. In the winter, noise from snowmobiles 

passing by the complex would also continue to 

be heard. It is possible that events, such as the 

Ford Ironman, would continue to occur (the 

Ford Ironman course currently runs through 

the complex and generates substantial noise). 

In addition, new residential development 

could occur on lands adjacent to the complex, 

which would result in noise during and after 

the construction period in these areas. 

These activities could produce intermittent 

to long-term (occurring every year) negligible 

to moderate adverse cumulative impacts 

from noise. The adverse impacts would vary 

depending on the type of noise, duration, 

and location. 

Alternative 1: No Action, Continuation of 

Current Management. If impacts of the above 

actions were added to the negligible adverse 

impacts under the no-action alternative, 

there would be long-term negligible to 

moderate adverse cumulative impacts on the 

soundscape. However, the cumulative impacts 

would primarily occur at certain times of the 

year — either seasonally or on weekends. 

The continuation of activities under the noaction alternative would result in a minimal 

contribution to the overall cumulative impacts.

Alternative 2: Ecological Restoration Emphasis.

If impacts of the above actions were added 

to the negligible to moderate adverse impacts 

under alternative 2, there would be long-term 

negligible to moderate adverse cumulative 

impacts on the soundscape. However, these 

cumulative impacts would primarily occur at 

certain times of the year – either seasonally 

or on weekends. The proposed activities 

under alternative 2 would result in a minimal 

contribution to overall cumulative impacts.

Alternative 3: Interpretation and Education 

Emphasis and Alternative 4: Outdoor Recreation 

Emphasis. If impacts of the above actions 

were added to the minor to moderate 

adverse impacts under alternatives 3 and 

4, there would be long-term minor to 

moderate adverse cumulative impacts on 

the soundscape. However, these cumulative 

impacts would primarily occur at certain times 

of the year – either seasonally or on weekends. 

The proposed activities under alternatives 3 

and 4 would result in a minimal contribution 

to overall cumulative impacts.

Alternative 5: Preferred Alternative. If impacts 

of the above actions were added to the 

negligible to moderate adverse impacts under 

alternative 5, there would be long-term minor 

to moderate adverse cumulative impact on 

the soundscape. However, these cumulative 

impacts would primarily occur at certain times 

of the year – either seasonally or on weekends. 

The proposed activities under alternative 5 

would result in a minimal contribution to 

overall cumulative impacts.

Vegetation and Wildlife

As noted in chapter 3, the Ice Age Complex 

comprises three ecological landscapes: 

Western Coulee and Ridges, Central Sand 

Hills, and Southeast Glacial Plains. Although 

this combination of landscapes in the complex 

indicates a variety of native vegetation, 

southern dry-mesic forest dominated the site 

before European settlement. 

The NPS Organic Act, which directs parks 

to conserve wildlife unimpaired for future 

generations, is interpreted by the agency 

to mean that native animal life should be 

protected and perpetuated as part of the park’s 

natural ecosystem. Natural processes are relied 
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT 99

Chapter Four Environmental Consequences

on to control populations of native species 

to the greatest extent possible, otherwise, 

they are protected from harvest, harassment, 

or harm by human activities. According to 

NPS Management Policies 2006 (section 4.1),

maintenance of natural ecosystems is a priority 

in parks. Management goals for wildlife include 

maintaining components and processes of 

naturally evolving park ecosystems, including 

natural abundance, diversity, and the ecological 

integrity of plants and animals.

Analysis Methodology

This impact analysis is based on knowledge 

of native and current vegetative conditions 

and wildlife habitat at the Ice Age Complex 

(as described in chapter 3), as well as an 

understanding of the types of activities (such 

as visitor activity, construction, and resource 

management) in parks that affect vegetation 

and wildlife. This general management plan / 

environmental impact statement does not 

include site-specific actions because the 

desired resource conditions and visitor 

experience, as described in the management 

area prescriptions and applied to each 

alternative, inform the impact assessment. 

The intensity levels used to evaluate impacts 

on vegetation and wildlife are provided below. 

Negligible. Impacts would have no measurable 

or perceptible changes in plant community 

size, integrity, or continuity. There would be 

no observable or measurable impacts on native 

species, their habitats, or the natural processes 

sustaining them. Impacts would be of short 

duration and well within natural fluctuations. 

Minor. Impacts would be measurable or 

perceptible but would be localized within a 

relatively small area. The overall viability of the 

plant community would not be affected and, 

if left alone, would recover. Impacts would be 

detectable, but they would not be expected 

to be outside the natural range of variability 

of key ecosystem processes and would not be 

expected to have any long-term effects on native 

species, their habitats, or the natural processes 

sustaining them. Population numbers, 

population structure, genetic variability, and 

other demographic factors for species might 

have small short-term changes, but long-term 

characteristics would remain stable and viable. 

Sufficient habitat would remain functional to 

maintain viability of all species. 

Moderate. Impacts would cause a change in 

the plant community (such as abundance, 

distribution, quantity, or quality); however, 

the impact would remain localized. Animals 

are present during particularly vulnerable 

life stages, such as migration, breeding, or 

juvenile stages. Mortality or interference 

with activities necessary for survival can 

be expected on an occasional basis but is 

not expected to threaten the continued 

existence of the species in the park unit. 

Impacts on native species, their habitats, or 

the natural processes sustaining them would 

be detectable, and they could be outside the 

natural range of variability for short periods 

of time. Population numbers, population 

structure, genetic variability, and other 

demographic factors for species might have 

short-term changes but would be expected to 

rebound to pre-impact numbers and remain 

stable and viable in the long term. 

Major. Impacts on the plant community 

would be substantial, highly noticeable, and 

permanent. Impacts on native species, their 

habitats, or the natural processes sustaining 

them would be detectable, and they would 

be expected to be outside the natural range 

of variability for long periods of time or be 

permanent. Population numbers, population 

structure, genetic variability, and other 

demographic factors for species might have 

large short-term declines, with long-term 

population numbers significantly depressed. 

Key ecosystem processes might be disrupted in 

the long term or permanently. Loss of habitat 

might affect the viability of at least some 

native species.
100 ICE AGE COMPLEX AT CROSS PLAINS

CHAPTER FOUR ENVIRONMENTAL CONSEQUENCES

Alternative 1: No Action, Continuation of 

Current Management — Direct and Indirect 

Impacts on Vegetation and Wildlife

There would be no comprehensive plan to 

guide management of the complex under 

alternative 1, so vegetation and wildlife 

habitat would not be consistently managed. 

Restoration goals (such as for the oak savanna 

or prairie) and activities (such as prescribed 

burning or mechanical invasive removal) 

would be decided on a case-by-case basis 

as funding and/or volunteer labor allows. 

Since there would be few defined trails, 

there would be a risk of vegetation trampling 

throughout the site from the creation of 

social trails. However, since the site would 

not be advertised, there would be no facilities 

to accommodate visitors, and user capacity 

management allows park managers a number 

of strategies to mitigate this risk; thus, adverse 

vegetation impacts from trampling would be 

negligible. It seems likely that, considering 

the site as a whole, there would be negligible 

impacts on vegetation and wildlife. 

Alternative 2: Ecological Restoration 

Emphasis — Direct and Indirect Impacts 

on Vegetation and Wildlife

Most of the complex would be managed 

for natural experience, in which “Natural 

resources are managed to approximate 

presettlement (circa 1830) conditions. To the 

extent possible, natural ecological processes 

sustain the integrity of these resources” (refer 

to the natural experience management area 

prescription for desired resource conditions 

in chapter 2, table 2). This management 

prescription would have a moderate beneficial 

impact on vegetation and wildlife. 

Alternative 3: Interpretation and 

Education Emphasis — Direct and Indirect 

Impacts on Vegetation and Wildlife

There would still be a significant area managed 

for natural experience, although most of the 

complex would be managed for landscape 

interpretation, under which the management 

prescription for resource conditions would 

include managing natural resources to reveal 

glacial features. Since there would be a range of 

ways to reveal glacial features through natural 

resource management (for example, planting 

short row crops or short prairie grasses), 

impacts on vegetation and wildlife would range 

from negligible to moderately beneficial. 

Alternative 4: Outdoor Recreation 

Emphasis and Alternative 5: Preferred 

Alternative — Direct and Indirect Impacts 

on Vegetation and Wildlife

Under these two alternatives, management 

prescriptions would be fairly evenly divided 

between landscape interpretation and 

expanded recreational experience (which 

share the same desired resource condition) 

and natural experience. Additionally, under 

alternative 5, a wildlife corridor of unbroken 

habitat would be established in the southern 

half of the complex. This combination of 

management prescriptions would result in 

minor beneficial impacts on vegetation 

and wildlife. 

Cumulative Impacts on Vegetation 

and Wildlife

Several potential actions, independent of this 

plan, could affect the complex’s vegetation 

and wildlife. As described in the “Affected 

Environment” chapter, some of the park’s 

vegetation and wildlife habitat has been 

altered by past human activities (including 

agricultural uses and development) and have 

also been altered due to the absence of fire. 

The impacts of these past actions far outweigh 

the impacts of the actions being proposed in 

the alternatives in this plan.

Residential development could occur in the 

future on lands adjacent to the complex, which 

would result in the loss and modification of 

vegetation, modification or loss of wildlife 

habitat, and the displacement of wildlife in 

these areas. This would have a long-term 

minor adverse impact on natural vegetation 

and wildlife in the vicinity of the complex. 
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT 101

Chapter Four Environmental Consequences

Hunting has affected wildlife in the past and 

would continue to affect wildlife as long as it 

continues to take place in the complex. 

The possible development of a bike path along 

Highway 14 and through the complex would 

affect vegetation in the area and possibly 

displace some wildlife, which would add a 

long-term minor adverse incremental effect to 

the effects from all alternatives.

As noted in the “Affected Environment” 

chapter, the spread of nonnative plants is 

currently a problem in the complex. Nonnative 

species have been spreading in different 

locations in the complex, such as around the 

Cross Plains gorge, in the old field, and in 

planted prairie areas, due to visitor activities 

and natural sources like wind and birds. 

In addition, even with education efforts, 

some nonnative plants could be introduced 

or spread by visitors in the park, such as at 

picnic areas, campsites, and along trails. It 

is difficult to determine the impact of these 

nonnative species on native vegetation due 

to the uncertainties about the type of species 

that might be introduced in the future and the 

locations and frequencies of introductions. 

The adverse effects from the introduction and 

spread of nonnative species could range from 

minor to moderate and be long term.

Alternative 1: No Action, Continuation of Current 

Management. If the effects of all the past, 

present, and future actions were added to the 

continuing negligible adverse impacts under the 

no-action alternative, there would be long-term 

minor to moderate adverse cumulative impacts 

on vegetation and wildlife in the complex. 

However, the effects of the no-action alternative 

would result in a minimal contribution to the 

overall adverse cumulative impacts.

Alternative 2: Ecological Restoration Emphasis; 

Alternative 3: Interpretation and Education 

Emphasis; Alternative 4: Outdoor Recreation 

Emphasis; and Alternative 5: Preferred Alternative. 

If the impacts of all past, present, and future 

actions were added to the impacts of 

alternatives 2, 3, 4, and 5, there would be longterm, minor to moderate adverse cumulative 

impacts on vegetation and wildlife in the 

complex. However, the effects of alternatives 2, 

3, 4, and 5 would not add to the overall adverse 

cumulative impacts because their actions 

would all be beneficial. 

SocioeconomicS

Social and economic goals are closely related 

and are therefore generally grouped together 

in this analysis as “socioeconomic impacts.” In 

this analysis, social impacts were determined 

by considering the goals that have been set by 

the local community and by judging the extent 

to which the alternatives would meet these 

goals. Economic impacts were determined by 

considering the impacts of each alternative on 

funding that would be available to the local 

government through tax receipts. 

The Village Board of Cross Plains, Wisconsin, 

adopted a new comprehensive plan on June 

9, 2008. Although the boundary of the village 

of Cross Plains is 1 mile from the northwest 

corner of the Ice Age Complex boundary, the 

comprehensive plan covers the extraterritorial 

boundary of the village, which includes 

unincorporated areas and overlaps with the 

complex on the northern end. The village’s 

comprehensive plan states the following vision 

for the planning area:

For the lands that comprise the Ice Age 

Complex, the comprehensive plan described 

most of the future land use as either agricultural/

rural or woodlands/open space. The exception 

to these two designations is for the lots that are 

currently residential. These current residential 

lots are zoned as “single-family exurban.” All 

of the alternatives in this general management 

plan / environmental impact statement are 

consistent with these zones for future land use, 

and therefore, all of them would have beneficial 

impacts on social goals because the Ice Age 

Complex would comprise a large open area for 

the town of Cross Plains. Preserving the natural 

state of this area would amount to a long-term 

moderate beneficial impact on social goals 

established for the village. There are differences, 

however, in how the alternatives would impact 

economic goals — these are discussed below. 
102 ICE AGE COMPLEX AT CROSS PLAINS

CHAPTER FOUR ENVIRONMENTAL CONSEQUENCES

Analysis Methodology

Property sales and income taxes are a large 

part of the economies of local governments. 

In order to determine the impacts on 

economic goals, it is necessary to consider 

the likely direction of the lands that comprise 

the Ice Age Complex if no alternatives 

were implemented and then compare that 

to the vision of each alternative. Under all 

alternatives, the National Park Service, the 

Wisconsin Department of Natural Resources, 

and their partners would seek to preserve 

as much open land as possible throughout 

the complex. This would mean that most 

potential for residential development would be 

removed, along with the property taxes these 

private residences would have paid. The extent 

to which payments in lieu of taxes would be 

made for publically owned lands depends on 

which of the project partners owns the land. 

Village of Cross Plains Overall Vision

“ l o o k i n g f o r wa r d t o 2 0 2 5 a n d b e y o n d , the Village desires a safe, clean, 

attractive and prosperous community that residents of all ages are proud to call home. There 

will be available a range of housing choices by price and features and a sustainable business 

environment. The rich natural resources of the Village and surrounding countryside and 

the Black Earth Creek in particular, will continue to be a defining feature of the community 

due to careful preservation efforts. Residents and visitors alike will be able to travel freely 

throughout the community by car, bike, or foot, and commuter transit service to Madison 

will reinforce the strong economic relationship with the metropolitan area. Though ties with 

Madison will strengthen, the Village will retain its character and identity.” 

The potential for property tax payments would 

be lost over the long term if the land were 

owned federally. Although local governments 

are eligible for federal payments in lieu of 

taxes to help offset losses in property taxes 

due to nontaxable federal property within 

their boundaries, historically, these payments 

have not kept pace with lost potential property 

tax revenue. However, for all new properties 

purchased, the Wisconsin Department of 

Natural Resources makes an annual payment 

in lieu of real estate taxes that would have been 

paid had the property remained in private 

ownership. The payment is made to the local 

taxing authority where the property is located.1

1

 Information on how the Wisconsin Department of 

Natural Resources pays property taxes can be found 

in a publication titled “Public Land Property Taxes” 

(publication number PUB-LF-001), available from 

the DNR.
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT 103

Chapter Four Environmental Consequences

The issue in determining the economic 

impacts of the alternatives is whether or not 

the potential loss of property tax would be 

offset by the economic benefits of visitation. 

The National Park Service uses an economic 

model called the “Money Generation Model” 

to estimate economic benefits of parks in 

terms of visitor spending (Stynes 2009). 

Unfortunately, data to feed into this model is 

not gathered for the Ice Age National Scenic 

Trail or for any other national trail. The 

analysis for the Ice Age Complex uses data 

from parks that are comparable in size and 

demographics to estimate potential economic 

benefits to the area around the complex. 

The intensity levels used to evaluate impacts on 

economic conditions are provided below. All 

impacts were compared to the most likely future 

for the complex over the 15- to 20-year term of 

this plan if none of the proposed alternatives 

were implemented. In that case (without 

implementation), as much as half of the land 

currently publically owned would potentially 

be developed as residences, while the other half 

would likely remain in agriculture. 

Negligible. No measurable effect on the 

economic environment.

Minor. Only a very small sector of the local 

and regional economies would be affected and 

would not be readily apparent.

Moderate. A small sector of the economic 

environment, or the relationship between 

sectors of the local and regional economies, 

would be measurably affected but would not 

alter basic economic functions and structure.

Major. Changes to the local and regional 

economies would occur and would become 

readily apparent in the form of shifts in 

economic functions and structure. In certain 

cases, entirely new economic sectors would be 

created or established sectors eliminated. 

Geographic Area for Socioeconomic Analysis.

The regional study area for the purpose of 

this socioeconomic impact analysis is Dane 

County, Wisconsin. Dane County is about 

1,200 square miles centered around the city 

of Madison. The Ice Age Complex is located 

in the northwestern part of Dane County. 

The west and northern county boundaries 

are roughly 10 miles from the complex, the 

southern boundary is roughly 20 miles away, 

and one would travel about 40 miles before 

crossing the eastern boundary of Dane County 

(refer to figure 13 in chapter 3).

All Alternatives — Direct and Indirect 

Impacts on Socioeconomics

All of the alternatives would produce 

beneficial impacts by increasing the value 

of adjacent lands. Similarly, all alternatives 

would have adverse impacts on the local tax 

base if lands were federally owned because 

federally owned land is exempt from property 

tax, and the payments in lieu of tax program 

historically has not fully compensated for 

this loss. However, these adverse impacts 

might be smaller than for similar areas of the 

National Park Service because the land would 

also be owned by the Department of Natural 

Resources, which would offset local property 

tax losses, so this potential tax loss would be 

mitigated. The impacts of land use changes 

were not considered separately in this analysis. 

Alternative 1: No Action, Continuation of 

Current Management and Alternative 2: 

Ecological Restoration Emphasis — Direct 

and Indirect Impacts on Socioeconomics

These two alternatives would only provide 

an outdoor experience in which activities 

for visitors would be limited to hiking and 

other low-impact activities on a minimal 

trail system and rare interpretive tours. The 

visitation level under these alternatives could 

be compared to the most sparsely visited 

parks (10,000 visitors per year or less) in 

the national park system. These parks, on 

average, contribute about $350,000 valueadded annually to their communities (valueadded is the sum of labor income, profits, 

rents, and indirect business taxes; see Stynes 
104 ICE AGE COMPLEX AT CROSS PLAINS

CHAPTER FOUR ENVIRONMENTAL CONSEQUENCES

2009, p. 6). Without knowing what type of 

housing would have been built if neither of 

these alternatives were implemented, it is 

impossible to know what the tax receipts 

would have been. If net property tax receipts 

from residential development (after the costs 

of improving infrastructure to accommodate 

these residences, such as schools and roads are 

taken into account) were to exceed $350,000 

annually, then the economic impacts of the 

no-action alternative and alternative 2 would 

be adverse. If, on the other hand, net property 

taxes were less than the estimated $350,000 

that visitation economic benefits would bring, 

the impacts of these two alternatives would 

be beneficial. 

Alternative 3: Interpretation and 

Education Emphasis — Direct and Indirect 

Impacts on Socioeconomics

This alternative would not only offer an 

outdoor experience, but also a place to stop 

and rest indoors, view some exhibits, and talk 

with park staff. Visitors would also benefit 

from regular interpretive programming 

provided by rangers. These elements would 

attract more visitors to the complex, but 

overall, the estimated visitation would 

still be relatively low. Visitation under this 

alternative could be compared to parks with 

low visitation (50,000–100,000 visitors per 

year) in the national park system. These parks, 

on average, contribute about $2.5 million 

value-added annually to their communities. It 

is not possible to know what the tax receipts 

would have been if this alternative is not 

implemented. If net property tax receipts 

from residential development (after the costs 

of improving infrastructure to accommodate 

these residences such as schools and roads 

are taken into account) were to exceed 

$2.5 million annually, then the economic 

impacts of alternative 3 would be adverse. If, 

on the other hand, net property taxes were less 

than the estimated $2.5 million that visitation 

economic benefits would bring, then the 

impacts of this alternative would be beneficial. 

Alternative 4: Outdoor Recreation 

Emphasis and Alternative 5: Preferred 

Alternative — Direct and Indirect Impacts 

on Socioeconomics

These alternatives would offer a broader 

outdoor experience in a variety of ways, such 

as more trails, limited primitive camping, 

picnic areas, and for alternative 4, a bridge 

across the gorge and a bike path. The two 

alternatives would also offer a place to stop 

and rest indoors; view extensive exhibits, 

including a film; and talk with park staff. There 

would be space to accommodate visitors 

who come in a group, such as school groups. 

Visitors would also benefit from regular 

interpretive programming provided by rangers. 

These elements would attract more visitors 

to the complex, and overall, the estimated 

visitation would fall in the moderate range 

for visitation (150,000–200,000 visitors per 

year) in the national park system (see the 

“Visitor Use and Experience” section for an 

explanation of expected visitation). These 

parks, on average, contribute about $5 million 

value-added annually to their communities. 

It is not possible to know what the tax 

receipts would be if these alternatives were 

not implemented. If net property tax receipts 

from residential development (after taking into 

account the costs of improving infrastructure, 

such as schools and roads, to accommodate 

the new residences ) were to exceed $5 million 

annually, then the economic impacts of these 

alternatives would be adverse. If, on the other 

hand, net property taxes were less than the 

estimated $5 million that visitation economic 

benefits would bring, then the impacts of these 

alternatives would be beneficial. 

Cumulative Impacts on Socioeconomics 

Residential and commercial growth and 

development could gradually increase in 

Dane County — this is according to the 

county population projections discussed in 

the “Affected Environment” chapter. Given 

the exurban nature of the lands surrounding 

the complex, much of the population 
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT 105

Chapter Four Environmental Consequences

increase would likely be absorbed by existing 

communities / employment centers with 

established infrastructure. The rate of growth 

would likely be slow but could result in new 

construction- and real estate-related jobs 

and new property tax revenue. If population 

growth were to occur, the addition of taxable 

property and consumer spending would likely 

have a beneficial impact on the socioeconomic 

environment over the long term. 

All Five Alternatives. If the likely effects of each 

of the five alternatives were combined with 

the potential effects of present and reasonably 

foreseeable future actions, there would be 

either long-term beneficial or long-term adverse 

cumulative impacts on the socioeconomic 

environment, depending on the nature and 

scope of any development on adjacent lands 

and the level of visitation to the complex. All 

five alternatives would contribute a very small 

increment to this cumulative impact. 

Visitor Use and Experience

As mentioned in chapter 3, the action 

alternatives were designed to respond, in 

various ways, to demand for low-impact 

passive recreational activities, as well as the 

opportunity to learn about glaciation of the 

area. An assumption of the planning team, 

based on a wealth of experience in park 

management, is that the greater the variety 

of things to do at a park, the more visitors 

it would attract. Therefore, it is expected 

that each alternative might attract a different 

number of visitors. 

Analysis Methodology

In order to estimate the number of expected 

visitors at the Ice Age Complex, the GMP/EIS 

planning team identified established comparable 

parks and researched their visitation counts. 

This comparison took into account state and 

local parks that are similar in theme and in size, 

as well as national parks in close proximity 

and in areas with similar demographics. Parks 

with similar themes used for comparison were 

the interpretive centers for units of the Ice Age 

National Scientific Reserve. While hiking the Ice 

Age National Scenic Trail is a popular activity 

in the state of Wisconsin, especially in densely 

populated areas like the city of Madison and 

vicinity, there are few destination areas along 

the trail where visitors can learn more about the 

unique geology and no learning opportunities 

in the Madison area. The Ice Age National 

Scenic Trail passes through two units of the Ice 

Age National Scientific Reserve. The two units 

have interpretive centers: Interstate State Park 

and Chippewa Moraine, which are both about 

200 miles from Madison. The Reserve Center 

at Interstate Park benefits from being part of a 

well-visited park and estimates 250,000 visitors a 

year. The Reserve Center at Chippewa Moraine, 

on the other hand, estimates only 20,000 visitors 

to its center per year, although staff there 

estimate higher visitation to the property. 

There are four parks within 20 miles of the 

Ice Age Complex that are about the same 

size as the complex; those four parks are 

Blue Mounds State Park, Governor Nelson 

State Park, Lake Kegonsa State Park, and the 

University of Wisconsin Arboretum. Visitation 

counts at these parks range from 150,000 to 

600,000. Lastly, the two units of the national 

park system used to estimate visitation were 

Effigy Mounds National Monument, the 

closest unit, and Wilsons Creek National 

Battlefield, which is similar demographically 

in that, like the Ice Age Complex, it is in the 

outskirts of a city (Springfield, Missouri) about 

the size of Madison. Effigy Mounds counts 

about 88,000 visitors a year; Wilsons Creek 

counts about 200,000. 

Considering all of the comparable estimates 

for visitation, the GMP/EIS planning team 

estimated that, if the Ice Age Complex were 

minimally developed with little interpretation 

(as in the no-action alternative and alternative 

2), the complex might attract only 10,000 

visitors per year. Those visitors would 

essentially be hikers on trails and participants 

in occasional programming. 
106 ICE AGE COMPLEX AT CROSS PLAINS

CHAPTER FOUR ENVIRONMENTAL CONSEQUENCES

On the other hand, if the complex were 

developed to offer a wider range of interpretive

and recreational opportunities (as in alternatives 

3, 4, and 5), the complex might attract as many as 

200,000 visitors per year. Among these 200,000 

would be groups of visitors, such as school 

groups, for whom special programming would 

be provided, as well as more casual visitors taking 

short hikes along well-developed trails. These 

visitation estimates were used in the analysis of 

socioeconomic impacts above, as well as in this 

analysis of visitor experience. 

The intensity levels used to evaluate impacts 

on visitor experience are provided below. 

The baseline against which these impacts 

were evaluated are the current conditions 

in which visitors are only aware that the 

complex contains publically owned parkland 

if they read the small signs at the boundary 

areas. The Ice Age National Scenic Trail is not 

constructed through the complex at this time, 

and the only existing trails are visitor-created 

social trails. Also, there is no interpretation. 

This baseline is different from the no-action 

alternative, which describes the future for the 

complex as it would evolve over the next 15–20 

years under current management strategies. 

Negligible. Visitors likely would not be aware 

of any additional opportunities to experience 

park resources.

Minor. Beneficial. Visitors would likely be 

aware of some additional opportunities to 

experience park resources but not a wide 

variety of different types of opportunities. 

They would be satisfied with the changes.

Adverse. Visitors would likely be aware of a 

decrease in opportunities to experience park 

resources and would be dissatisfied with 

the changes.

Moderate. Beneficial. Visitors would definitely 

be aware of additional opportunities to 

experience park resources in a variety of 

new ways. They would be very satisfied with 

the changes.

Adverse. Visitors would definitely be aware of 

a decrease in opportunities and/or diversity in 

opportunities and would be very dissatisfied 

with the changes. 

Major. Beneficial. Visitors would be highly aware 

of additional opportunities to experience park 

resources in a wide variety of new ways. They 

would be so satisfied with these changes that 

most new visitors would make the trip due to 

referrals from past visitors. 

Adverse. Visitors would be highly aware of a 

decrease in opportunities and/or diversity in 

opportunities and would be so dissatisfied with 

the changes that they would tell other potential 

visitors and visitation numbers would drop. 

Alternative 1: No Action, Continuation of 

Current Management and Alternative 2: 

Ecological Restoration Emphasis — Direct 

and Indirect Impacts on Visitor Experience 

These alternatives would only provide an 

outdoor experience in which activities for 

visitors would be limited to hiking and other 

low-impact activities on a minimal trail 

system and rare interpretive tours. While 

they activities would offer some beneficial 

experience for visitors over the current 

conditions, the benefits would likely range 

from negligible to minor. 

Alternative 3: Interpretation and 

Education Emphasis — Direct and Indirect 

Impacts on Visitor Use and Experience

This alternative would not only offer an 

outdoor experience, but also a place to stop 

and rest indoors, view some exhibits (not 

extensive given space limitations), and talk 

with park staff. Visitors would also benefit 

from regular interpretive programming 

provided by rangers. For visitors interested 

in the human history of the site, the ability 

to view and interpret the Wilkie house and 

barn would provide a pleasant variety of 

experience. However, visitors who might 
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT 107

Chapter Four Environmental Consequences

want to view a film in a theater or arrive in 

groups and gather in one indoor spot might be 

disappointed by the indoor space limitations. 

Overall, this alternative would offer beneficial 

visitor experience at a minor level. 

Alternative 4: Outdoor Recreation 

Emphasis — Direct and Indirect Impacts 

on Visitor Use and Experience

This alternative would offer a broad outdoor 

experience in a variety of ways (more trails, 

limited outdoor camping, picnic areas, a 

bridge across the gorge, and a bike path). 

It would also offer a place to stop and rest 

indoors; view extensive exhibits, including 

a film; and talk with park staff. There would 

be space to accommodate visitors who come 

in group, such as school groups. Visitors 

would also benefit from regular interpretive

programming provided by rangers. However, 

visitors seeking solitude and a quiet nature 

immersion experience might be disappointed 

to have to travel far from the core of the site 

to find this. Overall, this alternative would 

have a minor to moderate beneficial impact 

on visitor experience. 

Alternative 5: Preferred Alternative — 

Direct and Indirect Impacts on Visitor Use 

and Experience

This alternative would offer a broad outdoor 

experience in a variety of ways (more trails, 

including a half-day-long loop trail; limited 

outdoor camping; and picnic areas). It would 

also offer a place to stop and rest indoors; 

view extensive exhibits, including a film; and 

talk with park staff. There would be space to 

accommodate visitors who come in group, 

such as school groups. Visitors would also 

benefit from regular interpretive programming 

provided by rangers. Various attractions 

(such as a bike path traversing the site and a 

pedestrian bridge across the gorge) are not 

proposed in this alternative (as they are in 

alternative 4) because those amenities were 

not widely supported by the public when they 

commented on the preliminary alternatives. 

Therefore, it seems like not many benefits to 

visitor experience were lost with the removal 

of those elements. Because the sensitive 

resources management area was enlarged, 

visitors seeking solitude and a quiet nature 

immersion experience would not have to 

travel far from the core of the site to find this. 

Overall, this alternative would have a moderate 

beneficial impact on visitor experience. 

Cumulative Impacts on Visitor Use 

and Experience

There are no foreseeable actions in the 

complex or surrounding area that would 

likely cause adverse effects on visitor use 

and experience. There is the possibility of 

development on adjacent lands, which could 

affect viewsheds. Traffic volume could increase 

due to a slight increase in visitation or a 

change in visitor interests and demand due 

to potential changes in regional populations 

or national recreation trends. The likelihood 

of these changes is unknown at this time. If 

they were to occur, they could cause a slight 

increase in visitor use concerns, such as 

crowding and conflicts at high-use areas or 

attraction sites, or have adverse effects on the 

visitor experience commensurate with the 

extent to which developments would be visible 

and traffic would be audible from various 

visitor use areas within the complex. 

All of the Alternatives. The beneficial impacts 

on visitor experience from each of the five 

alternatives, when combined with other 

present and reasonably foreseeable future 

actions, would result in long-term negligible to 

minor adverse cumulative impacts, depending 

on the amount and location of development 

and level of increase in traffic volume. 

However, the development of the bike path 

would add a moderate beneficial increment to 

the overall cumulative impact. 
108 ICE AGE COMPLEX AT CROSS PLAINS

CHAPTER FOUR ENVIRONMENTAL CONSEQUENCES

Unavoidable 

Adverse Impacts

Unavoidable adverse impacts are defined here 

as major impacts that cannot be fully mitigated 

or avoided. No major adverse impacts are 

expected under any of the alternatives. It is 

expected that the development of trails and 

visitor, staff, and maintenance support areas 

at the core of the site would cause some 

impact. Those impacts, however, would 

be minimized through best construction 

practices, and any unexpected major adverse 

impacts would be mitigated. For example, if 

archeological resources were encountered 

during construction activities, mitigation 

measures would be implemented to protect 

those resources. 

Irreversible and 

Irretrievable Commitments 

of Resources

Implementing alternatives 3, 4, and 5 would 

likely result in the consumption of some 

nonrenewable natural resources in the form 

of construction materials and fuels that would 

constitute an irretrievable commitment of 

resources. There is also the potential for loss 

of archeological resources during construction 

projects. Future planning would examine this 

potential and would avoid or, if avoidance is 

not feasible, mitigate any loss. 

Relationship of Short-term 

Uses of Man’s Environment 

and Long-term Productivity

The first purpose of the Ice Age Complex 

at Cross Plains is to ensure protection, 

preservation, and interpretation of the 

nationally significant values of continental 

glaciation in Wisconsin. All five alternatives 

would achieve this purpose, and thus all of 

them would ensure long-term productive 

use of the complex. The only substantive 

development (“use of man’s environment”) 

would occur in a previously disturbed 

area. Outside the developed area, under all 

alternatives, productive ecosystem function 

would be maintained or restored throughout 

most of the complex, and where this is not 

feasible, the productivity of agricultural fields 

would remain.