Three Forks of the Missouri

A view from a promentory known as Lewis Lookout, over the valley where the Three Forks of the Gallatin, Madison, and Jefferson Rivers join to form the Missouri River.

NPS

On July 25, 1805, Lewis and Clark reached the headwaters of the Missouri River, a major objective of the expedition. Here, the Gallatin, Madison, and Jefferson Rivers form the Three Forks of the Missouri. Continuing westward, the expedition proceeded up the Jefferson River.22

Water quality in much of the Missouri River watershed is badly degraded. Drought conditions, low snowpack, and warmer temperatures brought on by climate change have led to low flows and fishing closures on several rivers. The Gallatin River has experienced noxious algae blooms since 2018. In 2021, the Madison River brown trout population reached a twenty-year low. Meanwhile, water temperatures in the Jefferson River became dangerously high for trout survival, at the same time as algae and low water flow impacted the river. The State of Montana and the U.S. Bureau of Reclamation cooperated to produce a Missouri Headwaters Basin Drought Contingency Plan in 2021.23

Citations:
22 NPS, “Three Forks of the Missouri,” Pittsburgh to the Pacific: High Potential Historic Sites of the Lewis and Clark National Historical Trail, 2022, 72, https://www.nps.gov/lecl/getinvolved/upload/2022_LCNHT_HPHS_Report_508compliantUPDATE-2.pdf; Meriwether Lewis, July 25, 1805 entry, in Gary E. Moulton, Journals of the Lewis and Clark Expedition, https://lewisandclarkjournals.unl.edu/item/lc.jrn.1805-07-25.
23 Quincey Johnson, “Missouri River Headwaters Sub-Basin Report—Summer 2021” Upper Missouri Water Keepers, June 30, 2021, https://www.uppermissouriwaterkeeper.org/basinreport21/; Ann Schwend, “Missouri Headwaters Basin Drought Contingency Plan” (Helena: Montana Department of Natural Resources and Conservation, August 2021), https://dnrc.mt.gov/_docs/water/Planning_implementation_coor/MTDNRCMissouriHeadwatersBasin.Aug.2021.pdf.

Climate Change:Lewis and Clark Trail

Lewis and Clark NHT Visitor Centers and Museums

This map shows a range of features associated with the Lewis and Clark National Historic Trail, which commemorates the 1803-1806 Lewis and Clark Expedition. The trail spans a large portion of the North American continent, from the Ohio River in Pittsburgh, Pennsylvania, to the mouth of the Columbia River in Oregon. The trail is comprised of the historic route of the Lewis and Clark Expedition, an auto tour route, high potential historic sites (shown in black), visitor centers (shown in orange), and pivotal places (shown in green). These features can be selected on the map to reveal additional information. Also shown is a base map displaying state boundaries, cities, rivers, and highways. The map conveys how a significant area of the North American continent was traversed by the Lewis and Clark Expedition and indicates the many places where visitors can learn about their journey and experience the landscape through which they traveled.