The greatest part of the Anaconda-Pintler Wilderness is located in the larger Beaverhead National Forest portion of , which is 64% of the total area of the forest. The rest of this wilderness extends into the neighboring Deerlodge and Bitterroot National Forests. The Beaverhead section includes most of the Pioneer, Gravelly, and Sapphire Ranges. Both the Centennial and Bitterroot mountain ranges are also located here, with the Continental divide found in the Bitterroot range. Lemhi Pass, at an elevation 7,323 feet (2,300 m) above sea level, is a rounded saddle in the Beaverhead Mountains of the Bitterroot Range, along the Continental Divide, between Montana and Idaho. Here, in 1805, the Lewis and Clark Expedition first saw the headwaters of the Columbia River, which flow to the Pacific Ocean, and crossed what was then the western boundary of the United States. Lemhi Pass was the point at which the members of the expedition realized that there was not a waterway that would lead from east to west across the continent. Lemhi Pass was designated a National Historic Landmark in 1960. The Lee Metcalf Wilderness, in the Madison mountain range, is a part of what is known as the Greater Yellowstone Ecosystem. However, most of the Lee Metcalf lies in neighboring Gallatin National Forest. The Beaverhead section lies, in descending order of land area, in parts of Beaverhead, Madison, Deer Lodge, and Silver Bow counties. There are local ranger district offices located in Dillon, Ennis, Wisdom, and Wise River.