Ice Age Complex 

a t c r o s s p l a i n s

FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT

Shoveler Sink

Snow covered gorge

Gorge in summer

National Park Service – U.S. Department of the Interior

Wisconsin Department of Natural Resources

Ice Age Complex at Cross Plains 

Wisconsin

This document establishes a framework to 

assist in making decisions about the Complex. 

It examines five alternatives for managing this 

site over the next 15 to 20 years, identifying 

desired conditions and analyzing the impacts 

of implementing each alternative. Alternative 

1: No Action, Continuation of Current 

Management looks into the future of 

current management and provides a basis for 

comparison to other alternatives. Alternative 

2: Ecological Restoration Emphasis would 

restore vegetative conditions to those present 

prior to European settlement, supporting 

interpretation of the post-glacial period. 

Alternative 3: Interpretation and Education 

Emphasis would focus on interpreting how 

the glacial landscape evolved over time, and 

ecological resources would be managed to 

reveal the glacial landscape. Alternative 4: 

Outdoor Recreation Emphasis would offer 

visitors a variety of low-impact recreational 

experiences supporting, and compatible 

with, the preservation and interpretation of 

glacial significance. Alternative 5: Preferred 

Alternative would provide interpretation 

of the landscape since glacial retreat 

and appropriate low-impact outdoor 

recreation opportunities. 

The potential environmental impacts of all 

alternatives have been identified and assessed. 

The following impact topics are addressed 

in this GMP/EIS: soil resources, water 

quality, soundscapes, vegetation and wildlife, 

socioeconomics, and visitor use and experience. 

The key impacts of Alternative 1 would be 

short and long-term, minor to moderate, 

adverse impacts on soils from agricultural 

use on some lands and unauthorized trails on 

others, but beneficial impacts to soils which 

are converted from farmland to prairie. There 

would be negligible to minor benefits to visitor 

experience under current management and 

negligible impacts in all other areas. 

The key impacts of Alternative 2 would be 

short and long term, mild to moderate, adverse 

impacts on soils from compaction from visitor 

use, but beneficial impacts to soils which are 

converted from farmland to prairie. There 

would be temporary adverse impacts to the 

soundscape from construction activities and 

a moderate beneficial impact on vegetation 

and wildlife from ecological restoration. There 

would be negligible to minor benefit to visitor 

experience under this alternative. 

Ice Age Complex at Cross Plains, Wisconsin 

FINAL General Management Plan/Environmental Impact Statement

T

h e I c e A g e C o m p l e x a t C r o s s P l ai n s , W i s c o n s i n comprises land within a 

unit of the Ice Age National Scientific Reserve and includes the interpretive site for the Ice Age 

National Scenic Trail. Within the Complex are lands owned and managed by the National Park 

Service, the Wisconsin Department of Natural Resources, Dane County Parks, and the U.S. Fish 

and Wildlife Service. This general management plan is needed to establish a consistent vision for 

the Ice Age Complex that is shared by all of these partners. 
The key impacts of Alternative 3 would be 

minor to moderate adverse impacts to soils 

from building and trail construction as well as 

compaction due to trail use, but also beneficial 

impacts to soils as they are converted from 

farmland to prairie. There would be minor to 

moderate adverse impacts to the soundscape 

from construction and increased visitation and 

a negligible to moderate beneficial impact on 

vegetation and wildlife. There would be minor 

benefit to visitor experience from indoor 

exhibits and interpretive programs.

The key impacts of Alternative 4 would be 

would be minor to moderate adverse impacts 

to soils from construction and trail use under 

this alternative, but also beneficial impacts 

to soils as they are converted from farmland 

to prairie. There would be minor beneficial 

impact on vegetation and wildlife. This 

alternative would have a minor to moderate 

benefit to visitor experience by offering broad 

outdoor experience and extensive exhibits. 

The key impacts of Alternative 5 would be 

minor to moderate adverse impacts on soils 

construction and trail use but also beneficial 

impacts to soils as they are converted from 

farmland to prairie. There would be minor 

beneficial impact on vegetation and wildlife 

under this alternative. This alternative would 

have a moderate benefit to visitor experience 

through broad outdoor experience and 

interpretive programming.

This General Management Plan/

Environmental Impact Statement was 

distributed to other agencies and interested 

organizations and individuals for review and 

comment. The public comment period for 

the document lasted for 60 days. For more 

information, contact Superintendent, Ice Age 

National Scenic Trail, 700 Rayovac Drive, 

Suite 100, Madison, Wisconsin 53711.
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT iii

Summary

Summary

Background

A mere 20,000 years ago, two-thirds of what 

is today the state of Wisconsin lay under the 

grip of colossal ice sheets. The climate warmed 

and the ice sheets began to melt back. They 

left in their wake an impressive landscape 

of fascinating glacial landforms: moraines, 

drumlins, kames, kettles, eskers, outwash plains, 

meltwater channels, driftless (unglaciated) 

topography, glacial lake beds and islands, and 

more. These Wisconsin Ice Age remnants are 

considered among the world’s finest examples 

of how continental glaciation sculpts our planet. 

Located just west of Madison near the town of 

Cross Plains is a 1,500-acre area that contains 

an outstanding collection of glacial landforms, 

including a gorge carved by meltwater and 

expansive views of both driftless and glaciated 

terrain. These acres comprise a park called, for 

the purpose of this planning effort, the “Ice Age 

Complex at Cross Plains” (henceforth “Ice Age 

Complex” or “complex”) (see figure ES-1). This 

site, however, has a rich history of different 

legal designations. 

The lands and landscape of the Ice Age Complex 

have been deemed nationally significant under 

two related, but distinct, federal designations. 

The elements recognized in both designations 

are parts of the singular concept advanced by 

Wisconsin citizens in the late 1950s and early 

1960s to protect and showcase Wisconsin’s 

heritage from continental glaciation. Congress 

authorized the concept in two parts, at two 

different times, and through two different 

legislative vehicles. 

In 1964 Congress enacted legislation (Public 

Law [PL] 88-655; 78 Stat. 1087; 16 United States 

Code [USC] 469d, et seq.) directing the Secretary 

of the Interior to cooperate with the governor 

of Wisconsin in studying and subsequently 

designating an Ice Age National Scientific 

Reserve (“Ice Age Reserve”). The purpose of 

the Ice Age Reserve is “to assure protection, 

preservation, and interpretation of the nationally 

significant values of Wisconsin continental 

glaciation, including moraines, eskers, kames, 

kettleholes, drumlins, swamps, lakes, and other 

reminders of the ice age.” The continental 

glaciers last advanced and retreated over the 

state some 30,000 to 10,000 years ago.

Congress envisioned the Ice Age Reserve as a 

network of distinct areas, each exhibiting an 

outstanding example of one type of landscape or 

landform resulting from continental glaciation. 

The legislation’s intention is that the reserve 

would be owned and managed by the state of 

Wisconsin, with the assistance and collaboration 

of the Secretary of the Interior (acting through 

the National Park Service). Several of the 

outstanding sites selected were already 

Wisconsin state parks. The legislation made 

reference to the Ice Age National Scenic Trail 

but made no provisions for it. 

When the study was completed, nine sites were 

identified to be protected and managed by the 

Wisconsin Department of Natural Resources 

(WDNR) as units of the Ice Age Reserve (see 

figure ES-2). On May 29, 1971, the Secretary of 

the Interior published an order in the Federal 

Register that formally brought the Ice Age 

Reserve into existence. 

As noted in Black (1974), “The Cross Plains 

area was selected for inclusion in the Reserve in 

part because it contains a typical portion of the 

Johnstown Moraine on the uplands and a typical 

proglacial stream in Black Earth Creek Valley, 

and is close to a center of population. More 

importantly, it is the only place . . . where the 

terminal moraine rests directly on well exposed, 

weathered dolomite bedrock and where small 

marginal proglacial lakes, a marginal drainage 

way, and a subglacial drainage way may all be 

seen in a small area. The various glacial features 

associated with the moraine in the vicinity of 

Cross Plains are more varied and yet as definitive 

as one could hope to see, all preserved in a neat 

little package. The area is one of increasing 

urbanization, and preservation of parts of the 

front and its associated phenomena can only be 

assured in the Reserve.” 
iv ICE AGE COMPLEX AT CROSS PLAINS

SUMMARY

Figure ES-1: Map of Ice Age Complex at Cross Plains

Publically Protected Lands

Proposed Area for Ice Age NST

Cross Plains Ice Age Complex

Proposed Addition

UW Regents

Dane County

Municipal

National Park Service

Fish & Wildlife Service

WI DNR

WI DOT

July 2012

­ 0 500 1,000 Feet

Shoveler

Sink

Coyle

Pond

\\INPMWROGSCSRV03\Projects\IATR\Cross_Plains_Complex\Cross_Plains_Ownership_8x11_July2012.mxd Timber Lane

Wisconsin 

DNR

Wisconsin 

DNR

Wisconsin 

DNR

Dane

County

Dane

County

National

Park Service

Fish & Wildlife

Service

Goth

Park
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT v

Summary

Figure ES-2: Ice Age National Scientific Reserve and Its Nine Units
vi ICE AGE COMPLEX AT CROSS PLAINS

SUMMARY

The Wisconsin Department of Natural 

Resources purchased 100 acres of the 

Cross Plains unit of the Ice Age Reserve in 

September 1975, and an additional 60 acres 

were subsequently purchased. The Cross 

Plains unit is also designated as Cross Plains 

State Park by Wisconsin Administrative Rule. 

Congress again recognized the national 

significance of Wisconsin’s glacial landscapes 

when, on October 3, 1980, it amended the 

National Trails System Act to authorize and 

establish the Ice Age National Scenic Trail as 

a component of the National Trails System 

(PL 96-370; 94 Stat. 1360; 16 USC 1244(a)(10)). 

The Ice Age National Scenic Trail meanders 

through Wisconsin for approximately 

1,200 miles from Potawatomi State Park in 

Door County to Interstate State Park in Polk 

County, generally following the terminal 

moraine and other glacial landscape features 

and connecting six of the nine units of the 

Ice Age Reserve. The Secretary of the Interior 

was assigned administrative responsibility for 

the Ice Age National Scenic Trail.

The Secretary of the Interior delegated overall 

administrative responsibility for the Ice Age 

National Scenic Trail to the National Park 

Service. The Park Service, in cooperation 

with the Wisconsin Department of Natural 

Resources and other parties, completed a 

Comprehensive Plan for Management and 

Use of the Ice Age National Scenic Trail 

in September 1983. The National Park 

Service is responsible at the federal level for 

carrying out the provisions of the National 

Trails System Act as they relate to the Ice Age 

National Scenic Trail. The National Park 

Service carries out or facilitates trail planning, 

environmental compliance, trail development 

and management, public and private partner 

involvement, and land protection activities. 

The National Park Service assists partners 

by coordinating, guiding, and assisting their 

efforts to acquire, develop, operate, protect, 

and maintain the Ice Age National Scenic Trail 

in accordance with the comprehensive plan 

and supplemental trail corridor plans and 

trailway protection strategies (land protection 

plans). The comprehensive plan identifies the 

Wisconsin Department of Natural Resources 

and the nonprofit Ice Age Trail Alliance as 

cooperators in the long-term effort to develop 

and manage the Ice Age National Scenic 

Trail. The Park Service serves as the primary 

liaison with other federal agencies in matters 

relating to the Ice Age National Scenic Trail. 

In carrying out this role, the Park Service 

reviews and comments on federal or federally 

assisted/permitted projects and activities (such 

as highway, utility, and other development 

proposals) that may affect trail segments.

The Wisconsin Department of Natural 

Resources is the state agency responsible 

for providing and maintaining outdoor 

recreation resources of statewide 

significance, including state parks and 

trails, in Wisconsin. Thus, the basis for the 

Wisconsin Department of Natural Resources’ 

participation in developing and managing 

the Ice Age Reserve and Ice Age National 

Scenic Trail is the statewide significance of 

the reserve and trail and the inclusion of state 

parks, forests, trails, and recreation areas in 

the reserve and along the route of the trail. 

The state legislature formalized this role in 

1987 by passing legislation that designates 

the Ice Age National Scenic Trail as a State 

Scenic Trail. The legislation assigned the 

responsibility to the Wisconsin Department 

of Natural Resources for coordinating the 

involvement of state agencies in the trail 

project and cooperating with the National 

Park Service and private interests in planning, 

acquiring, developing, and maintaining the 

Ice Age National Scenic Trail. The Wisconsin 

Department of Natural Resources has been 

the primary NPS partner in administering 

federal financial assistance for acquiring 

lands for the Ice Age National Scenic Trail.

The National Trails System Act authorizes 

the establishment of interpretive sites along 

national scenic trails. Congress appropriated 

funds, in fiscal year (FY) 2001, for the 

acquisition of specific lands, owned by James 

and Jane Wilkie, for an Ice Age National Scenic 
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT vii

Summary

Trail Interpretive Site. The lands specified for 

the interpretive site happen to lie within the 

boundaries of the Cross Plains unit of the 

Ice Age Reserve. The National Park Service 

purchased the lands in 2002, subject to a life 

estate, and took full possession in early 2008.

The Wilkie farmstead includes a stone house, 

the original two-story portion of which 

dates back to the 1850s, just a few years after 

statehood in 1848. The one-story addition, 

built with stone from the same quarry as the 

original house, dates to 1952 when the Wilkies 

purchased the farm. There is also a structurally 

sound wood barn, modern garage, shed used 

as a chicken coop, and Quonset for equipment 

storage. These structures are referred to 

elsewhere in this document as the “farmstead” 

or individually as the “stone house,” “barn,” 

and so forth. The structures were evaluated for 

eligibility to be listed on the National Register 

of Historic Places, but it was determined they 

were not historically significant.

The lands that comprise the Ice Age Complex 

are managed at both a state and federal level. 

That is, the Ice Age Reserve is owned and 

managed by the state of Wisconsin, and the 

Ice Age National Scenic Trail Interpretive Site 

is owned and managed by the National Park 

Service. Additionally, the Ice Age Complex also 

includes Shoveler Sink Waterfowl Production 

Area, which is owned and managed by the U.S. 

Fish and Wildlife Service. The involvement of 

both federal and state governments, as well 

as Dane County Parks, makes this plan to 

preserve and interpret the Ice Age Complex a 

true partnership effort. 

Purpose of the Plan

The final general management plan would 

provide a framework to assist NPS and WDNR 

managers in making decisions today and in 

the future. The alternatives proposed in this 

document describe general paths the National 

Park Service and Department of Natural 

Resources would follow in managing the Ice 

Age Complex over the next 15 to 20 years. 

This general management plan / environmental 

impact statement

identifies desired conditions in different 

parts of the Ice Age Complex

identifies any necessary developments 

and support facilities to achieve the 

vision and desired conditions

ensures that the foundation for 

decision making has been developed 

in consultation with the public and 

adopted by NPS leadership after 

sufficient analysis of the benefits, 

impacts, and economic costs of 

alternative courses of action

This document addresses the three purposes 

listed above, but it does not

describe how particular programs or 

projects would be implemented or 

prioritized; these decisions are deferred 

to detailed implementation planning 

provide specific details and answers to 

all the issues facing the Ice Age Complex

provide funding commitments for 

implementation of the plan 

Need for the Plan

The general management plan is needed 

in order to establish a consistent vision for 

the Ice Age Complex that is shared by all 

partners in this project. Those partners 

are the National Park Service, Wisconsin 

Department of Natural Resources, U.S. 

Fish and Wildlife Service, Ice Age Trail 

Alliance, local government agencies, and the 

general public. Although the Department 

of Natural Resources’ 1998 feasibility study 

provided a rough outline for how the Ice 

Age Complex could be managed, the final 

general management plan would be the first 

plan designed to provide comprehensive 

management guidance for the complex. 
viii ICE AGE COMPLEX AT CROSS PLAINS

SUMMARY

The Ice Age National Scenic Trail is guided 

by a 1983 comprehensive management plan, 

and the Ice Age Reserve is guided by a 1968 

comprehensive management plan. Neither 

of these older overarching plans, however, 

articulates the shared vision between the 

National Park Service, Department of 

Natural Resources, and the public on how to 

best achieve the specific purpose of the Ice 

Age Complex and protect its resources for 

future generations.

Currently, the Ice Age Complex is essentially 

undeveloped for visitor use. Given its location 

just outside the fast-growing suburbs of 

Madison, Wisconsin, and the interest in Ice 

Age geology in the region, there is potential for 

significant visitation at the complex. There is 

also potential for damage to the glacial features 

at the site without long-term planning for their 

protection. Thus, this general management 

plan is needed because 

the management plans for related areas 

(national scenic trail and scientific 

reserve) are outdated

there must be a consistent and shared 

vision for the complex 

there is potential for both significant 

visitation and resource damage

The Five Alternatives

This general management plan / environmental 

impact statement examines five alternatives 

for managing the Ice Age Complex. In all of 

the alternatives, NPS managers will continue 

to strive to protect, maintain, and monitor 

key resources. Each alternative proposes a 

different approach to managing resources, 

serving visitors, and providing interpretive 

and recreational opportunities.

Alternative 1: No Action, Continuation of 

Current Management 

This alternative describes how the Ice Age 

Complex would look in the future if no new

actions were taken. The description for the 

no-action alternative was used as a baseline 

against which to assess the benefits, costs, and 

impacts of action alternatives 2, 3, 4, and 5. 

The Ice Age Complex is undeveloped for 

visitor use and minimally maintained. Both 

the Wisconsin Department of Natural 

Resources and U.S. Fish and Wildlife Service 

manage vegetation on lands that each agency 

owns and on land owned by the National 

Park Service. Staff members for the Ice Age 

National Scenic Trail have stabilized facilities 

to prevent their deterioration. There are 

currently no improvements (such as parking or 

constructed trails) on either WDNR- or NPSowned lands to facilitate visitor experience. 

The Shoveler Sink Waterfowl Production 

Area, managed by the U.S. Fish and Wildlife 

Service, is open to visitors for hunting, fishing, 

and other wildlife-dependent activities, but 

the production area has no visitor facilities 

other than two small unsurfaced parking lots. 

Privately owned lands in the complex consist 

of agricultural fields, along with several homes 

and their outbuildings.

The segment of the Ice Age National Scenic 

Trail would still be built (by the Ice Age Trail 

Alliance) within the identified corridor under 

this alternative, but other trails would not 

be constructed. 

Boundary Expansion. The boundary of the Ice 

Age Complex would not be expanded.

Estimated Costs and Staffing. A staff of six 

full-time equivalents would be required to 

implement this alternative and administer 

the Ice Age National Scenic Trail across the 

state. The annual operating costs (in 2010 

dollars) would be approximately $560,000, 

including costs for resource management, 

employee salaries and benefits, and leasing 

office space. The total one-time costs would 

be approximately $1.24 million (in 2010 

dollars) for stabilizing the Wilkie property 

and purchasing seed to reestablish natural 

vegetation conditions. The one-time costs 

would not include the cost of land protection, 

such as acquisition or easements. 
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT ix

Summary

Alternative 2: Ecological 

Restoration Emphasis

The ecosystem throughout most of the site 

would be restored to vegetative conditions that 

were present prior to European settlement 

(circa 1830). The restoration would support 

interpretation of how natural conditions in 

the complex would have evolved after the 

glacial period under minimal human influence. 

Vegetation would be managed at key points 

to reveal glacial landscapes, but the focus 

would be on ecosystem management. Visitors 

would enjoy a sense of perceived remoteness 

and quiet, primarily by hiking on trails. The 

management concept in alternative 2 would be 

implemented by

restoring presettlement vegetation 

by applying natural processes 

wherever possible 

removing the buildings at the core of the 

site that belonged to the Wilkie family 

and providing parking and trail access at 

this location, as well as outdoor exhibits 

and primitive restrooms 

providing a minimally developed trail to 

and along the rim of Cross Plains gorge 

interpreting the site with wayside and 

outdoor exhibits 

managing the complex from an offsite location — there would be no 

permanent staff stationed at the site, and 

visitor interaction with park staff would 

be rare 

Boundary Expansion. The boundary of the Ice 

Age Complex would not be expanded.

Estimated Costs and Staffing. A staff of eight 

full-time equivalents would be required to 

implement this alternative, together with 

administering the Ice Age National Scenic 

Trail across the state. The work required to 

administer the Ice Age National Scenic Trail 

overlaps significantly with the work required 

to manage the Ice Age Complex; therefore, 

staffing estimates for this alternative cover 

both of these functions. The annual operating 

costs (in 2010 dollars) would be approximately 

$760,000 to pay for resource management, 

employee salaries and benefits, and leasing 

office space. The total one-time costs would 

be approximately $1.94 million (in 2010 

dollars) for removing the Wilkie structures, 

constructing trails, and purchasing seed to 

reestablish natural vegetation conditions over 

more acreage than the no-action alternative. 

The one-time costs would not include the 

cost of land protection (such as acquisition 

or easements). 

Alternative 3: Interpretation and 

Education Emphasis

The glacial landscape would be interpreted to 

focus on how the Ice Age Complex has evolved 

over time since the retreat of the last glacier. 

Throughout most of the complex, ecological 

resources would be managed to reveal the 

glacial landscape. Visitors would have an 

opportunity to experience a wide variety of 

resources, both ecological and geological, as 

well as remnants of human use of the site. The 

visitor experience would involve sheltered 

and indoor settings at the core of the property 

and hiking throughout most other areas of the 

site. Trails would be placed to tell stories of 

the formation of the glacial landscape and, to 

a lesser extent, about the ecological resources, 

such as the oak savanna. Under this alternative, 

the Ice Age Complex would serve as the 

headquarters for the Ice Age National Scenic 

Trail. This management concept would be 

implemented by

renovating the house and/or barn 

at the core of the site for reuse to 

accommodate visitor orientation, while 

interpreting human use and settlement 

patterns; space in these facilities would 

also be renovated for use as staff offices

constructing a new facility at the 

core of the site to accommodate 

maintenance needs
x ICE AGE COMPLEX AT CROSS PLAINS

SUMMARY

requesting the town of Cross Plains 

to manage traffic along Old Sauk Pass 

between Cleveland Road and North 

Birch Trail to reduce hazards 

to pedestrians 

providing a trail to and along the gorge 

with overlooks, surfaced at least in part 

to accommodate people with disabilities, 

as well as controlled partial access along 

the floor of the gorge

preserving and enhancing key views 

through vegetation management 

(for example, by selective thinning 

and pruning)

expanding the complex boundary 

westward to include WDNR-owned 

land and enhance opportunities to 

interpret a wider expanse of driftless 

area terrain

Boundary Expansion. Alternative 3 proposes to 

expand the boundary of the Ice Age Complex, 

as well as the boundary of Cross Plains State 

Park. The boundary would be expanded to 

include a 228-acre WDNR-protected parcel. 

The Department of Natural Resources owns 

part of the parcel in full, and part of it is 

privately owned and protected by an easement. 

The parcel is recommended for incorporation 

into the complex’s boundary in order to 

include and protect significant resources and 

values and to enhance opportunities for public 

enjoyment related to park purpose. The parcel 

would offer visitors an expansive view of the 

Driftless Area, a rare sight along the Ice Age 

National Scenic Trail. 

Estimated Costs and Staffing. A staff of 

10.5 full-time equivalents would be required 

to implement this alternative and administer 

the Ice Age National Scenic Trail across the 

state. The work required to administer the 

Ice Age National Scenic Trail would overlap 

significantly with the work required to manage 

the Ice Age Complex; therefore, staffing 

estimates for alternative 3 would cover both 

of these functions. The annual operating costs 

(in 2010 dollars) would be approximately 

$1.01 million, including costs for resource 

management, employee salaries and benefits, 

and maintenance and operations. The total 

one-time costs would be approximately $4.74 

million (in 2010 dollars) and would go toward 

renovating the Wilkie property, designing 

and installing exhibits, constructing trails 

and a maintenance facility, and purchasing 

seed to reestablish natural vegetation 

conditions. The one-time costs would not 

include the cost of land protection, such as 

acquisition or easements. 

Alternative 4: Outdoor 

Recreation Emphasis

Visitors would be offered a variety of lowimpact outdoor recreational experiences in 

support of, and compatible with, preserving 

and interpreting the glacial significance of 

the complex and restoring and managing 

the ecosystem. Visitors would be able to 

experience resources in diverse ways and 

would enjoy a broad range of interpretive 

programming in indoor and outdoor settings. 

Under this alternative, the Ice Age Complex 

would serve as the headquarters for the Ice 

Age National Scenic Trail. This management 

concept would be implemented by

developing the core of the complex to

renovate the Wilkie house and barn 

primarily for use as staff offices 

selectively site and construct a 

new visitor center with orientation 

services (such as exhibits and film)

selectively site and construct a new 

maintenance facility, unless future 

land acquisitions would allow for 

this development away from the 

core of visitor activity

provide outdoor gathering 

spaces such as an amphitheater 

and picnic shelter
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT xi

Summary

requesting the town of Cross Plains to 

manage access to Old Sauk Pass between 

Cleveland Road and North Birch Trail 

(same as proposed under alternative 3)

providing a trail to and along the gorge 

with overlooks that would be surfaced, 

at least in part, to accommodate people 

with disabilities. If feasible a pedestrian 

bridge spanning the gorge would be built 

to provide visitors a unique perspective 

on its formation

providing extensive, varied trails, 

including a hardened bicycle/pedestrian 

trail across the site 

offering primitive camping in the 

western section of the complex 

expanding the complex’s boundary 

westward to enhance opportunities for 

recreation, especially for a primitive 

camping experience near the Ice Age 

National Scenic Trail

Boundary Expansion. The boundary of the Ice 

Age Complex would be expanded to include 

the same 228-acre WDNR-protected parcel 

(mentioned under alternative 3). This parcel 

would be necessary to enhance opportunities 

for public enjoyment related to park purpose. 

There is no appropriate area for camping along 

the Ice Age National Scenic Trail corridor 

within the current complex boundary, so the 

parcel would be managed for an expanded 

recreational experience to allow for primitive 

camping for hikers on the Ice Age National 

Scenic Trail, which would traverse this area. 

This addition would be feasible to manage for 

the same reasons cited under alternative 3. 

Estimated Costs and Staffing. A staff of 

14 full-time equivalents would be required 

to implement this alternative and administer 

the Ice Age National Scenic Trail across 

the state. The annual operating costs (in 

2010 dollars) would be approximately 

$1.26 million, including costs for resource 

management, employee salaries and benefits, 

and maintenance and operations. The 

total one-time costs of approximately $8.8 

million (in 2010 dollars) would be spent on 

renovating the Wilkie property; designing 

and installing exhibits; constructing trails, a 

maintenance facility, and a new visitor center; 

and purchasing seed to reestablish natural 

vegetation conditions. The one-time costs 

do not include the cost of land protection 

(acquisition or easements). 

Alternative 5: Preferred Alternative

This alternative would provide visitors with 

interpretation of the evolution of the complex 

from the last glacial retreat and opportunities 

to enjoy appropriate low-impact outdoor 

recreation. Ecological resources would largely 

be managed to reveal the glacial landscape. 

The most sensitive ecological areas would be 

carefully protected, and visitor access would 

be highly controlled in these areas. Visitors 

would experience a wide variety of indoor and 

outdoor interpretive programming. Under this 

alternative, the Ice Age Complex would serve 

as the headquarters for the Ice Age National 

Scenic Trail. 

The management concept for alternative 5 

would be implemented by developing the 

core of the site (the former Wilkie property) 

to accommodate offices for Ice Age National 

Scenic Trail staff (who would support 

administrative and maintenance functions) 

and provide for a visitor center, including a 

sheltered picnic area. The elements involved in 

developing the site include

producing a building complex that 

would be highly sustainable (the 

overall goal of this development); 

certified under the U.S. Green Building 

Council’s Leadership in Energy and 

Environmental Design rating system 

at a gold level; have a minimal carbon 

footprint; and employ systems to 

carefully control surface water runoff 

and avoid impacting the quality of Black 

Earth Creek. 
xii ICE AGE COMPLEX AT CROSS PLAINS

SUMMARY

retaining parts of the existing house 

and barn to the extent that is practical 

given the need for a cost-effective, 

environmentally sustainable visitor 

center, office space, and space to 

support maintenance functions. 

Ultimately, the design of the core area 

for public and operational use would 

reflect public feedback as well as cost 

and environmental factors. 

Until the visitor center, office, and 

maintenance facility complex described above 

can be funded and constructed, the existing 

buildings in the core area may be minimally 

modified, as necessary, to make them useful on 

an interim basis as a visitor contact station and 

for maintenance and storage purposes. 

The management concept for alternative 5 

would also be implemented by

requesting the town of Cross Plains 

to manage traffic along Old Sauk 

Pass between Cleveland Road and 

North Birch Trail to reduce hazards 

to pedestrians (same as alternatives 3 

and 4)

providing a trail leading to and along 

the gorge with overlooks surfaced at 

least in part to accommodate people 

with disabilities. Vegetation in the 

gorge would be restored and volunteer 

trails removed.

Additionally, the management concept for 

alternative 5 would be implemented by

providing an extensive, varied hiking 

trail network throughout the complex

providing a management area in a 

narrow strip along U.S. Highway 14 

to accommodate a bicycle path (in the 

planning stages) to connect Middleton 

to Cross Plains. This alternative does not 

envision the National Park Service or 

the Wisconsin Department of Natural 

Resources building the bicycle path; 

rather, the agencies would accommodate 

local efforts to build the path 

offering primitive camping equipped 

with a privy in the western part of 

the complex 

establishing a wildlife corridor of 

unbroken habitat between the former 

Wilkie property and Shoveler Sink. 

The area of this corridor is defined as 

“landscape interpretation” because 

of the abundance of opportunity to 

view glacial features here. While the 

landscape interpretation management 

area generally allows for agricultural 

fields, the intent of landscape 

interpretation in this particular 

corridor is to return the land to a type 

of native vegetation (such as short 

prairie grasses rather than tall prairie 

grasses) that would not obscure the 

view of glacial features 

providing picnic tables next to parking 

areas along U.S. Highway 14 and along 

Mineral Point Road 

Boundary Expansion. Alternative 5 proposes 

to expand the complex boundary westward 

to incorporate two expansion areas (parcels). 

The one parcel would be the same 228-acre 

WDNR-protected parcel (mentioned 

above under alternatives 3 and 4), and the 

other would be a 40-acre parcel protected 

and owned by the Department of Natural 

Resources. Both parcels would be necessary to 

enhance opportunities for public enjoyment 

related to park purpose under this alternative. 

Both parcels would be managed for an 

expanded recreational experience to allow for 

primitive camping for hikers on the Ice Age 

National Scenic Trail, which would traverse 

this area, and for hiking on other trails. 

Estimated Costs and Staffing. A staff of 14 

full-time equivalents would be required to 

implement this alternative and administer the 

Ice Age National Scenic Trail across the state. 

The annual operating costs (in 2010 dollars) 
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT xiii

Summary

would be approximately $1.26 million, 

including costs for resource management, 

employee salaries and benefits, and 

maintenance and operations. The total onetime costs of approximately $7.09 million (in 

2010 dollars) would be spent on renovating 

the Wilkie property and new construction 

within the core area, designing and installing 

exhibits, constructing trails, and purchasing 

seed to reestablish natural vegetation 

conditions. The one-time costs would not 

include the cost of land protection, such as 

acquisition or easements. 

Impacts from 

Implementation of 

the Alternatives

Soil Resources

Alternative 1: No Action, Continuation of Current 

Management. 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 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 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 Ice Age National Scenic Trail would still 

be built under this alternative but other trails 

would not. Over time, unauthorized trails 

(such as paths created by visitors), would 

proliferate. 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 

and 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 were not accompanied 

by measures to protect these areas, such as a 

designed and delineated trail, damage to the 

steep walls could 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. 
xiv ICE AGE COMPLEX AT CROSS PLAINS

SUMMARY

Alternative 2: Ecological Restoration Emphasis.

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.

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. 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. 

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 an adverse 

moderate 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. 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 
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT xv

Summary

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 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. 

Water Quality

Alternative 1: No Action, Continuation of Current 

Management. 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.

The small basin that collects surface water 

flowing into the Coyle Pond would be put 

back into presettlement vegetation under 

this alternative, and any adverse impact on 

groundwater would be negligible. 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. 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. 

Soundscapes

Alternative 1: No Action, Continuation of Current 

Management. 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 visitor-created noise. It seems likely that, 

overall, there would be negligible impacts on 

the soundscape. 

Alternative 2: Ecological Restoration Emphasis.

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. Alternative 3 would result in a 

considerable increase in visitation compared 

to the no-action 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 
xvi ICE AGE COMPLEX AT CROSS PLAINS

SUMMARY

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.

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. Impacts 

on the soundscape 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. 

Vegetation and Wildlife

Alternative 1: No Action, Continuation of 

Current Management. There would be no 

comprehensive plan to guide management 

of the complex, 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 would allow 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.

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.” 

This management prescription would have a 

moderate beneficial impact on vegetation 

and wildlife. 

Alternative 3: Interpretation and Education 

Emphasis. 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. 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, 
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT xvii

Summary

a wildlife corridor of unbroken habitat would 

be established in the southern half of the 

complex. This combination of management 

prescriptions would entail a minor beneficial 

impact on vegetation and wildlife. 

Socioeconomics

All Alternatives. Typically, the addition of 

parklands to a community increases the value 

of land adjacent to the park. Because of this, all 

of the alternatives would be likely to produce 

beneficial economic impacts. Similarly, all 

alternatives would have adverse impacts on the 

local tax base if lands were federally owned 

because those lands would be 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 does offset local property 

tax losses, so this potential tax loss could 

be mitigated. 

Alternative 1: No Action, Continuation of 

Current Management and Alternative 2: 

Ecological Restoration Emphasis. These two 

alternatives would only provide an outdoor 

experience in which activities for visitors 

would be limited to hiking and other lowimpact 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 value-added annually to their 

communities. 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. 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 were 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. 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 
xviii ICE AGE COMPLEX AT CROSS PLAINS

SUMMARY

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. 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.

Visitor Use and Experience

Alternative 1: No Action, Continuation of Current 

Management and Alternative 2: Ecological 

Restoration Emphasis. 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 

the 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 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 

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.

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. 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. 
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT xix

Summary

Next Steps 

and Implementation of the 

General Management Plan

A 60-day public review and comment 

period on this general management plan / 

environmental impact statement has been 

completed. After the comment period, the 

NPS planning team evaluated comments from 

other federal agencies, tribes, organizations, 

businesses, and individuals regarding this 

document and incorporated appropriate 

changes into a final general management plan / 

environmental impact statement. The final 

document includes letters from government 

agencies, any substantive comments on the 

draft document, and NPS responses to 

those comments. 

There will be a 30-day no-action period 

following distribution of the final general 

management plan / environmental impact 

statement. A “record of decision” may be 

prepared that would document the NPS 

selected alternative, which would become 

the new general management plan for the 

Ice Age Complex to be implemented over 

15 to 20 years. Once a record of decision is 

signed by the NPS regional director, the plan 

would then be implemented as funding and 

staffing allows. 

i t i s i m p o r t a n t t o n o t e that not all 

of the actions in the selected alternative would 

necessarily be implemented immediately. 

The implementation of the approved 

plan, no matter which alternative might be 

selected, would depend on future NPS, 

state, and partner funding levels; staff to 

implement the plan; servicewide priorities; 

and on partnership time and effort. Full 

implementation of the plan could be many 

years in the future. 

Please Note
xx ICE AGE COMPLEX AT CROSS PLAINS

SUMMARY
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT xxi

Contents

Contents

CHAPTER ONE Introduction and Purpose and Need for a General Management Plan 3

Introduction 3

Description of the Ice Age Complex 3

Overview of the Planning Process 8

Purpose of the Plan 10

Need for the Plan 10

Foundation Statement 11

Statements of Park Purpose 11

Statements of Park Significance 11

Fundamental and Other Important Resources and Values 12

Primary Interpretive Themes 12

Legal and Policy Requirements 14

Scope of the General Management Plan 20

Issues and Concerns Addressed in this Plan 20

Issues and Concerns Not Addressed in this Plan 20

Impact Topics 20

Relationship of Other Planning 

Efforts to this General Management Plan 27

U.S. Highway 14 Access Study 27

Bike Path Along U.S. Highway 14 27

Town of Cross Plains Comprehensive Plan 27

Village of Cross Plains Comprehensive Plan 27

Next Steps in the Planning Process 28

Implementation of the Plan 28

Wisconsin State Property Designation 28

Chapter TWO Alternatives, Including the Preferred Alternative 31

Formulation of the Alternatives 31

Identification of the Preferred Alternative 

and Environmentally Preferred Alternative 32

Consideration of Boundary Adjustment(s) 32

User Capacity 34

The Proposed Alternatives 34

Management Areas 36

The Alternatives Considered 36

Alternatives Considered but Dismissed 51

Estimated Costs and Staffing (in 2010 dollars) 

of the Five Alternatives 53
xxii ICE AGE COMPLEX AT CROSS PLAINS

CONTENTS

User Capacity 54

Indicators and Standards 56

Priority Visitor Experience Indicators and Standards 59

Long-term Monitoring 60

Needed Future Studies and Plans 60

Environmentally Preferred Alternative 61

Preferred Alternative 63

Comparison of the Alternatives 63

Chapter THREE Affected Environment 75

Geologic and Soil Resources 75

Bedrock Geology 76

Soils 81

Water Quality 81

Soundscapes 82

Vegetation and Wildlife 82

Socioeconomics 84

Visitor Experience 85

Chapter FOUR Environmental Consequences 89

Definitions for Evaluating Effects 90

Types of Effects 90

Duration of Effects 90

Intensity of Effects 90

Past, Present, and Reasonably Foreseeable Future 

Actions On or In the Vicinity of the Ice Age Complex 90

Soil Resources 91

Analysis Methodology 91

Alternative 1: No Action, Continuation of Current Management — 

Direct and Indirect Impacts on Soils 91

Alternative 2: Ecological Restoration Emphasis — 

Direct and Indirect Impacts on Soils 92

Alternative 3: Interpretation and Education Emphasis — 

Direct and Indirect Impacts on Soils 93

Alternative 4: Outdoor Recreation Emphasis — 

Direct and Indirect Impacts on Soils 93

Alternative 5: Preferred Alternative — 

Direct and Indirect Impacts on Soils 93

All Alternatives — Cumulative Impacts on Soils 94
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT xxiii

Contents

Water Quality 94

Analysis Methodology 94

Alternative 1: No Action, Continuation of Current Management — 

Direct and Indirect Impacts on Water Quality 95

Alternative 2: Ecological Restoration Emphasis — 

Direct and Indirect Impacts on Water Quality 95

Alternative 3: Interpretation and Education Emphasis; 

Alternative 4: Outdoor Recreation Emphasis; and 

Alternative 5: Preferred Alternative — 

Direct and Indirect Impacts on Water Quality 95

Cumulative Impacts on Water Quality 95

Soundscapes 96

Analysis Methodology 96

Alternative 1: No Action Alternative, Continuation of Current Management — 

Direct and Indirect Impacts on the Soundscape 97

Alternative 2: Ecological Restoration Emphasis — 

Direct and Indirect Impacts on the Soundscape 97

Alternative 3: Interpretation and Education Emphasis — 

Direct and Indirect Impacts on the Soundscape 97

Alternative 4: Outdoor Recreation Emphasis — 

Direct and Indirect Impacts on the Soundscape 97

Alternative 5: Preferred Alternative — 

Direct and Indirect Impacts on the Soundscape 97

Cumulative Impacts on the Soundscape 98

Vegetation and Wildlife 98

Analysis Methodology 99

Alternative 1: No Action, Continuation of Current Management — 

Direct and Indirect Impacts on Vegetation and Wildlife 100

Alternative 2: Ecological Restoration Emphasis — 

Direct and Indirect Impacts on Vegetation and Wildlife 100

Alternative 3: Interpretation and Education Emphasis — 

Direct and Indirect Impacts on Vegetation and Wildlife 100

Alternative 4: Outdoor Recreation Emphasis and Alternative 5: Preferred Alternative — 

Direct and Indirect Impacts on Vegetation and Wildlife 100

Cumulative Impacts on Vegetation and Wildlife 100

Socioeconomics 101

Analysis Methodology 102

All Alternatives — Direct and Indirect Impacts on Socioeconomics 103

Alternative 1: No Action, Continuation of Current Management and Alternative 2: 

Ecological Restoration Emphasis — Direct and Indirect Impacts on Socioeconomics 103

Alternative 3: Interpretation and Education Emphasis — 

Direct and Indirect Impacts on Socioeconomics 104

Alternative 4: Outdoor Recreation Emphasis and Alternative 5: Preferred Alternative — 

Direct and Indirect Impacts on Socioeconomics 104

Cumulative Impacts on Socioeconomics 104
xxiv ICE AGE COMPLEX AT CROSS PLAINS

CONTENTS

Visitor Use and Experience 105

Analysis Methodology 105

Alternative 1: No Action, Continuation of Current Management and Alternative 2: 

Ecological Restoration Emphasis — Direct and Indirect Impacts on Visitor Experience 106

Alternative 3: Interpretation and Education Emphasis — 

Direct and Indirect Impacts on Visitor Use and Experience 106

Alternative 4: Outdoor Recreation Emphasis — 

Direct and Indirect Impacts on Visitor Use and Experience 107

Alternative 5: Preferred Alternative — 

Direct and Indirect Impacts on Visitor Use and Experience 107

Cumulative Impacts on Visitor Use and Experience 107

Unavoidable Adverse Impacts 108

Irreversible and Irretrievable Commitments of Resources 108

Relationship of Short-term Uses of Man’s Environment and Long-term Productivity 108

Chapter FIVE Consultation and Coordination 111

Public Involvement 111

Tribal Consultation 112

Federal Agencies Consultation 113

Wisconsin State Historic Preservation Office Consultation 113

Consultation Letters and Responses 114

appendixes, references, and index 121

Appendix A: Laws Establishing the Ice Age National Scientific Reserve 

and the Ice Age National Scenic Trail 121

Appendix B: Town of Cross Plains Resolution Regarding Old Sauk Pass 125

Appendix C: Wisconsin Department of Natural Resources Compliance Form 127

Appendix D: Acronyms and Abbreviations 128

Appendix E: Planning Team 129

Appendix F: Comment/Response Report 131
FINAL GENERAL MANAGEMENT PLAN ENVIRONMENTAL IMPACT STATEMENT xxv

Contents

FIGURES

ES-1: Map of Ice Age Complex at Cross Plains iv

ES-2: Ice Age National Scientific Reserve and its nine units v

1: Ice Age Complex at Cross Plains 5

2: Ice Age National Scientific Reserve and Its Nine Units 6

3: Expanded Boundary Changes and Inclusion of Parcels A and B 35

4: Overview of the Ice Age Complex at Cross Plains 40

5: Map for Alternative 2: Ecological Restoration Emphasis 42

6: Map for Alternative 3: Interpretation and Education Emphasis 44

7: Map for Alternative 4: Outdoor Recreation Emphasis 46

8: Map for Alternative 5: Preferred Alternative 49

9: NPS User-Capacity Framework 55

10: Distribution of near-surface bedrock units at the Ice Age Complex 77

11: North-south cross-section through the Ice Age Complex 78

12: Detailed map of glacial and related deposits in the Ice Age Complex 79

13: Map of Dane County and the Ice Age Complex 84

TABLES

1: NPS Mandates and Policies 16

2: Five Management Areas for the Ice Age Complex 37

3: Estimated Costs of Implementing Each of the Five Alternatives 55

4: Indicators, Management Areas, Standards, and Potential Management Strategies 56

5: Six Criteria for Assessing the Environmentally Preferred Alternative 62

6: Summary of the Key Elements of the Alternatives 64

7: Summary Comparison of Impacts of the Alternatives 68
xxvi ICE AGE COMPLEX AT CROSS PLAINS

CONTENTS