NPS Geodiversity Atlas—Big Hole National Battlefield, Montana

Geodiversity refers to the full variety of natural geologic (rocks, minerals, sediments, fossils, landforms, and physical processes) and soil resources and processes that occur in the park. A product of the Geologic Resources Inventory, the NPS Geodiversity Atlas delivers information in support of education, Geoconservation, and integrated management of living (biotic) and non-living (abiotic) components of the ecosystem.

tepee and mountains

National Park Foundation Photo.


Big Hole National Battlefield (BIHO) is located about 160 km (100 mi) southwest of Helena, Montana along the eastern Bitterroot Range in Beaverhead County, southwestern Montana. Established as a military preserve in 1883, BIHO was designated a national monument on June 23, 1910 and redesignated a national battlefield on May 17, 1963 (National Park Service 2016a). In 1992, BIHO was legislatively added as an administrative unit of Nez Perce National Historical Park (NEPE, covered in its own section below). Encompassing approximately 409 hectares (1,011 acres), BIHO pays tribute to the battle between the Nez Perce and the 7th U.S. Infantry forces with Montana citizen volunteers on August 9–10, 1877. The battle is considered a key event within a five-month conflict in which the army was intent on moving the Nez Perce to the Lapwai Reservation in Idaho. Along the way, a series of confrontations between the two sides would lead to the death of 90 Nez Perce and 31 soldiers.

Geologic Setting

BIHO is named after Big Hole Valley, one of the highest and widest mountain valleys of western Montana. The valley separates the Pioneer Mountains along its eastern margin from the Bitterroot Range on the west and contains a thick fill of sedimentary material such as sand, clay, mud, and gravel that overlie deeply buried volcanic rocks. The bedrock geology of BIHO is predominantly composed of rocks associated with the Eocene–Miocene Bozeman Group and related valley-fill deposits. Younger Quaternary alluvium (unconsolidated deposits of gravel, sand, silt, or mud) are mapped within BIHO along the transect of the North Fork of the Big Hole River and its tributaries.

Regional Geology

Big Hole National Battlefield is a part of the Northern Rocky Mountain System Physiographic Province and shares its geologic history and some characteristic geologic formations with a region that extends well beyond park boundaries.

Maps and Reports

The Geologic Resources Inventory produces digital geologic maps and reports for more than 270 natural resource parks. The products listed below are currently available for this park, check back often for updates as many maps, reports, and posters are still in progress.
  • Scoping summaries are records of scoping meetings where NPS staff and local geologists determined the park’s geologic mapping plan and what content should be included in the report.
  • Digital geologic maps include files for viewing in GIS software, a guide to using the data, and a document with ancillary map information. Newer products also include data viewable in Google Earth and online map services.
  • Reports use the maps to discuss the park’s setting and significance, notable geologic features and processes, geologic resource management issues, and geologic history.
  • Posters are a static view of the GIS data in PDF format. Newer posters include aerial imagery or shaded relief and other park information. They are also included with the reports.
  • Projects list basic information about the program and all products available for a park.

Source: Data Store Saved Search 2719. To search for additional information, visit the Data Store.

NPS Soil Resources Inventory project has been completed for Big Hole National Battlefield and can be found on the NPS Data Store.

Source: Data Store Saved Search 2773. To search for additional information, visit the Data Store.

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Big Hole National Battlefield

National Park Service Geodiversity Atlas

The servicewide Geodiversity Atlas provides information on geoheritage and geodiversity resources and values within the National Park System. This information supports science-based geoconservation and interpretation in the NPS, as well as STEM education in schools, museums, and field camps. The NPS Geologic Resources Division and many parks work with National and International geoconservation communities to ensure that NPS abiotic resources are managed using the highest standards and best practices available.

Big Hole National Battlefield

Last updated: June 17, 2024