In the late 1990s, scientists from the U.S. 

Geological Survey (USGS) met with counterparts from the U.S. Forest Service (USFS) 

to discuss what geologic information was 

needed from the USGS to support current 

management objectives for forest lands. The 

forest plan revision process, planning regulations, and timetables were reviewed and two 

topics were identifi ed that could be addressed 

by the USGS. The highest priority need was 

for a regionally consistent, digital geologic 

map that could be integrated with other natural-resource data to address a wide range of 

land-use issues. The other need was for minerals information that would indicate where 

minerals-related activities might take place in 

the near future.

Geologic map.—The digital geologic map 

prepared by the USGS is in a format approprias printed maps. Working with state agencies, 

the USGS converted the remaining printed 

maps to a digital format. The maps used 

included new geologic maps for the Salmon 

and Payette National Forests and several 

100,000-scale quadrangle maps published 

by the USGS and the Idaho Geological Survey. Integrating these various maps into one 

was challenging because they used different 

standards and included inconsistencies across 

political boundaries, which made interpretation of the geology diffi cult and time consuming. Consequently, the datasets were reviewed 

and extensive revisions were made to provide 

the information in consistent, accessible, and 

user-friendly formats to maximize their usefulness to the USFS.

Minerals information.—Regional datasets 

and studies of areas with mineral potential will 

help the USFS understand where future minerals-related activities may take place. Besides 

geology, regional datasets include the locations of active mines and signifi cant mineral 

deposits and geophysical datasets that provide 

information about the distribution of rocks beneath the surface. USGS scientists and collaborators studied the large, undeveloped copper 

deposits in northern Idaho and northwestern 

Montana and copper-cobalt deposits in Idaho. 

The Salmon River fl ows along the fault-bounded Lemhi Valley in the Salmon National Forest. Regional compilation of geologic mapping in digital formats by the U.S. Geological Survey supports U.S. Forest Service land-use 

planning for this region. (USGS photograph by Arthur A. Bookstrom.)

ate for regional planning (scale 1:100,000 

to 1:250,000) in the 

USFS geographic 

information system 

(GIS). This product 

was created from 

digital versions of 43 

geologic maps. Only 

23 of those maps were 

already in a digital 

format; the others 

were available only 

The U.S. Forest Service is working to 

integrate geoscience information 

USGS Fact Sheet 2005-3155

2005

U.S. Department of the Interior

U.S. Geological Survey

120° 118° 116° 114° 112° 110° 108°

42°

43°

44°

45°

46°

47°

48°

49°

IDAHO

MONTANA

OREGON

WYOMING

WASHINGTON

NEVADA UTAH

Nampa

Missoula

Billings

Kennewick

Pocatello

Boise

Great Falls

Idaho

Falls

0 90 MILES 45

0 120 KILOMETERS 60

Spokane

EXPLANATION

Regional

compilation

National Forest

Northern Rocky 

Mountains

physiographic

province

boundary

Cities

Interstate 

highways

State boundaries

into land-use planning processes. To 

help achieve this goal, U.S. Geological 

Survey (USGS) Mineral Resource Program scientists are providing a wealth 

of information, including geologic maps, 

databases (geology, mineral locality, 

geochemical, and geophysical), and 

mineral assessments for the Northern 

Rocky Mountains of Idaho, Montana, 

and Washington. This area is known for 

its world-class deposits of gold, copper, 

silver, platinum, garnet, and talc and has 

been the site of a variety of mineral resource assessment studies by the USGS.

Mineral Resources Research Supports Land-Use Planning in 

the Northern Rocky Mountains

Regional setting of the area 

of U.S. Geological Survey 

compilation of digital geologic mapping designed to 

support U.S. Forest Service 

goal of integrating geoscience information into landuse planning. 
Printed on recycled paper

Michael L. Zientek and Susan J. Kropschot

Other studies looked at the relation between 

mineral deposits and the locations of ancient 

faults and at the geochemistry of mined and 

unmined geologic terrains.

Collaborative research has been an important part of this endeavor. The digital geologic 

map includes information collected through 

cooperative research agreements with the 

Idaho Geological Survey and the Montana Bureau of Mines and Geology. Cooperative studies of geology and forest management with the 

University of Idaho and USFS Rocky Mountain Research Station, Moscow, infl uenced the 

design of the digital geologic map database. 

The USGS, the USFS, and the University of 

Montana worked together to compile data on 

garnet resources in northern Idaho. Contracts 

with exploration geologists provided access 

to private-sector exploration data on copper 

and lead-zinc mineralization hosted by sedimentary rocks. Data on mining claims and on 

minerals-related permits were compiled with 

the cooperation of the USFS and U.S. Bureau 

of Land Management.

The resulting information is being used by 

the USFS to model different scenarios relating 

to land use, forest health, and landslide and 

wildfi re hazards, as well as for the assessment 

of the mineral resource potential, which is critical to planning future mineral exploration and 

mining in the forests. The fi nal datasets generated by this project provide the ability to combine different datasets so that planning can, in 

the words of one USFS manager, “provide the 

best solutions to problems of all types.”

Because the amount of technical information about the Northern Rocky Mountains 

was overwhelming, USGS scientists provided 

interpretive summaries of the different datasets to facilitate their usefulness in the forest 

planning process. For example, the 2,100 map 

units in the digital geologic map compilation 

are diffi cult to understand and illustrate; the 

USGS provided information for each unit 

that allows derivative maps to be constructed 

based simply on rock type—an example is the 

generalized geologic map shown below. The 

new digital datasets have enabled USFS managers to analyze huge amounts of geologic, 

geochemical, geophysical, and mineral-locality information over the entire project area at 

consistent map scales with relative ease. 

The information in geologic datasets have 

long been used to understand Earth history; 

assess mineral, energy, and water resources; 

and delineate hazards related to Earth processes. The same information in the new 

digital format can now be used more easily 

by USFS planners to help delineate ecological units based on landform, rock type, 

soil, and vegetation (such as land type associations) or disturbance regimes (areas that 

would have similar response to disturbances 

such as fi res, road construction, and timber 

harvest). The ability to combine different datasets will allow a better understanding of the 

relation between geology and ecosystems and 

will support decisions about threatened and 

endangered species, as well as future mineral 

exploration and development.

For further information, contact:

U.S. Geological Survey

904 W. Riverside Avenue, Room 202

Spokane, WA 99201-1087

(509) 368-3105

Email: mzientek@usgs.gov

For the digital geologic map, see U.S. Geological Survey 

Open-File Report 2005-1235 (available online at 

http://pubs.usgs.gov/of/2005/1235 )

For more information on other related products, see U.S. 

Geological Survey Open-File Report 2005-1382 (available 

online at http://pubs.usgs.gov/of/2005/1382 )

This Fact Sheet and any updates to it are available online at

http://pubs.usgs.gov/fs/2005/3155

For additional information visit:

http://minerals.usgs.gov/

117° 115° 113° 111° 109°

43°

44°

45°

46°

47°

48°

49° EXPLANATION

Unconsolidated

deposits

Siliciclastic-rich

sedimentary and 

metasedimentary

rocks

Carbonate-rich

sedimentary and 

metasedimentary

rocks

Sedimentary and 

metasedimentary

rocks rich in 

volcanic rock 

fragments

Other sedimentary 

rocks

Igneous and 

metamorphosed

igneous rocks

Other metamorphic 

rocks

Tectonite

0 90 45 MILES

0 120 60 KILOMETERS

Edited by Peter H. Stauffer

Graphic design by Susan Mayfi eld

COOPERATING ORGANIZATIONS

Idaho Geological Survey

Montana Bureau of Mines and Geology

University of Idaho

University of Montana

U.S. Bureau of Land Management

U.S. Forest Service

Burnt Knob in the Bitterroot Mountains of northeastern Idaho (foreground) and forest-fi re scar along ridge 

crossed by the Nez Perce Trail. This area contains critical habitat for threatened and endangered species, such 

as grizzly bears, salmon, and bull trout, posing land-use management issues that are supported by new digital 

datasets from the U.S. Geological Survey. (USGS photograph by Arthur A. Bookstrom.)

Recent digital compilation of geologic 

datasets allowed U.S. 

Geological Survey 

scientists to generate this generalized 

geologic map of 

the Northern Rocky 

Mountains. The 

information in the dataset can be used to 

understand Earth history; assess mineral, 

energy, and water 

resources; and delineate hazards related 

to Earth processes. 

Datasets can be combined with other information to produce 

ecological units, key 

to U.S. Forest Service 

forest management.

MONTANA

WASH

IDAHO

OREGON

WYOMING

INDEX MAP