Big Hole National Battlefield: Where the Nez Perce Fought in 1877, and the Valley Beneath

Big Hole National Battlefield lies about 160 km (100 mi) southwest of Helena, Montana, along the eastern Bitterroot Range in Beaverhead County. It covers about 409 hectares (1,011 acres).

The battle

The battlefield honors the fight of August 9–10, 1877, between the Nez Perce and the 7th U.S. Infantry with Montana citizen volunteers. It was a key event in a five-month conflict in which the Army set out to move the Nez Perce to the Lapwai Reservation in Idaho; along the way, a series of clashes left 90 Nez Perce and 31 soldiers dead.

The valley

The battlefield takes its name from the Big Hole Valley, one of the highest and widest mountain valleys of western Montana. The valley divides the Pioneer Mountains on the east from the Bitterroot Range on the west, and holds a thick fill of sand, clay, mud and gravel over deeply buried volcanic rocks.

• The battlefield's bedrock is mostly rocks of the Eocene–Miocene Bozeman Group and related valley fill.
• Younger Quaternary alluvium — loose gravel, sand, silt and mud — lines the North Fork of the Big Hole River and its tributaries.

The battlefield belongs to the northern Rocky Mountain System Physiographic Province and shares its geologic history with a region far beyond the park.

Trail Creek valley, Big Hole National Battlefield. Image from the National Park Service's page on the battlefield's geodiversity

Maps and surveys

This page is part of the NPS Geodiversity Atlas, from the Geologic Resources Inventory, which makes digital geologic maps and reports for more than 270 natural resource parks. The battlefield's scoping summaries, digital geologic maps, reports and posters are in the NPS DataStore, and an NPS Soil Resources Inventory of it has been completed (DataStore).

More: geologic formations · photo gallery · park home.

Sources

Based on "NPS Geodiversity Atlas—Big Hole National Battlefield, Montana," National Park Service, citing National Park Service (2016); a work of the United States government in the public domain. Its opening photograph, credited to the National Park Foundation, is not reproduced.