Major Rivers in Yellowstone
Gallatin River: The Gallatin River begins inside the park north of the Madison River. It flows north through Gallatin Canyon and across the Gallatin Valley, joining the Madison and Jefferson rivers at Three Forks, Montana, to form the Missouri River.
Gibbon River: The Gibbon River flows from Grebe Lake through the Norris area to Madison Junction.
Firehole River: The Firehole River starts south of Old Faithful and flows through the park’s major hydrothermal basins north to Madison Junction.
Madison River: The Madison River begins at Madison Junction where the Gibbon and Firehole Rivers come together.
Snake River: The Snake River—a major tributary of the Columbia River—has its headwaters just inside Yellowstone on the Two Ocean Plateau, at a point on the Continental Divide. The river flows through Idaho and joins the Columbia in Washington. The Snake River is 1,040 miles long; 42 miles of it are in Yellowstone National Park.
Bechler River: The Bechler River is the major river in the southwestern portion of the park and is known for its waterfalls. The Bechler begins just north of Pitchstone Plateau, on the Pacific side of the Continental Divide, and empties into the Falls River, along the park’s southern boundary. It was named after Gustavus Bechler, topographer on the second Hayden Survey (1872).
Lamar River: The Lamar River is a tributary of the Yellowstone River, approximately 40 miles long and is located entirely within the park. It rises in the Absaroka Range, on the eastern edge of the park, and flows northwest through its northeast corner. It is joined by many tributary streams, including Soda Butte Creek and Slough Creek and joins the Yellowstone near Tower Junction, just below the Grand Canyon of the Yellowstone.
Yellowstone River: Yellowstone River begins outside the park on Younts Peak and flows into Yellowstone Lake. It leaves the lake at Fishing Bridge, and continues north-northwest until it leaves the park near Gardiner, Montana. The Yellowstone River continues north and east through Montana and joins the Missouri River just over the North Dakota state line
Major Lakes in Yellowstone
Yellowstone Lake: Yellowstone Lake is the largest body of water in Yellowstone National Park. The lake is 7,732 feet above sea level and covers 136 square miles with 110 miles of shoreline. While the average depth of the lake is 139 feet, its deepest spot is at least 390 feet. Yellowstone Lake is the largest freshwater lake above 7,000 feet in North America. In winter, ice nearly 3 feet thick covers much of the lake, except where shallow water covers hot springs. The lake freezes over by early December and can remain frozen until late May or early June.
Shoshone Lake: Shoshone Lake is a backcountry lake with the area of 8,050 acres located in the southwest section of the park. It lies at the headwaters of the Lewis River, a tributary of the Snake River. The U.S. Fish and Wildlife Service believes that Shoshone Lake is the largest backcountry lake in the lower 48 states that cannot be reached by a road.
Lewis Lake: Lewis Lake is located in the southern part of the park, about 4 miles southeast of Shoshone Lake, and approximately 10 miles southwest of Yellowstone Lake. Lewis Lake and Shoshone Lake are both located a few miles northeast of the Pitchstone Plateau. The Lewis River is the lake’s primary inflow, draining south from Shoshone Lake. The primary outflow of Lewis Lake is also the Lewis River, continuing south to join the Snake River near the southern boundary of the park. A few small creeks also feed Lewis Lake. There are several hot springs emptying into the lake on its northwestern shore and two more hot springs at the lake’s southern end where it empties into the Lewis River. A campground is located on the lake’s southeast shore. The South Entrance Road runs along the east side of Lewis Lake. Like the river, Lewis Lake is named for Meriweather Lewis, commander of the Lewis and Clark Expedition.
Heart Lake: Heart Lake is a large backcountry lake, nestled at the base of Mount Sheridan in the southern part of the park. Heart Lake is in the Snake River drainage and is drained by the Heart River. It is 7.5 miles from the south entrance road at Lewis Lake via the Heart Lake trail. Heart Lake can also be reached via the Trail Creek trail that traverses the southern shoreline of Yellowstone Lake or via the Heart River trail/Snake River trail from the park’s southern border.
Isa Lake: Isa Lake straddles the continental divide at Craig Pass and was first discovered in 1891 by Hiram M. Chittenden, who was exploring the best routes for a road to connect Old Faithful and West Thumb geyser basins. Chittenden named the lake after Isabel Jelke, though it is unclear why. Isa Lake is believed to be the only lake in the world which drains to two different oceans backwards. The east side of the lake drains by way of the Lewis River to the Pacific Ocean and the west side of the lake drains by way of the Firehole River to the Atlantic Ocean. This is the opposite of what one would expect since the Atlantic Ocean is east of the lake and the Pacific Ocean is to the west. The lake is easy to visit as it is adjacent to the road that now connects the Old Faithful and West Thumb geysers basins.
Grebe Lake: Grebe Lake is a 156 acres backcountry lake that forms the headwaters of the Gibbon River. Grebe Lake is located approximately 3.1 miles north of the Norris-Canyon section of the Grand Loop Road. The trail to the lake passes through mostly level Lodgepole Pine forest and open meadows. The lake was named by J.P. Iddings, a geologist with the Arthur Hague geologic surveys.
Trout Lake: Trout Lake (formerly known as Fish Lake and Soda Butte Lake) is a 12 acre, popular backcountry lake for hikers and anglers in the northeast section of the park. The lake is located approximately 1/3 of a mile north of the Northeast Entrance Road near the confluence of Pebble Creek and Soda Butte Creek. The lake sits in a depression on a high bench above the Soda Butte Creek canyon, and was once used as a fishery for the production of trout by the USFWS. A steep trail through a Douglas Fir forest leads to the lake, and can be accessed via the Trout Lake trailhead. The lake is a popular area for viewing River Otter.