Lost Trail National Wildlife Refuge, Nature reserve in Flathead County, United States.

Lost Trail National Wildlife Refuge covers 8,834 acres of prairie and wetlands in Flathead County, Montana, about 40 miles west of Kalispell via U.S. Highway 2. It was formerly the Lost Trail Ranch, a horse and cattle operation dating to the late 19th century. The refuge has few improvements and is not permanently staffed.

The refuge was established in 1999 on the site of the Lost Trail Ranch, a horse and cattle operation dating to the late 19th century. It is among the newest National Wildlife Refuges in the United States and is managed by the U.S. Fish and Wildlife Service as part of the Western Montana National Wildlife Refuge Complex.

The refuge occupies the former Lost Trail Ranch, a horse and cattle operation dating to the late 19th century; the ranch name carried over to the federal refuge created in 1999. Visitors today see prairie and wetland where livestock once grazed, and the site is managed by the U.S. Fish and Wildlife Service as part of the Western Montana National Wildlife Refuge Complex.

The refuge is located west of Kalispell along Highway 2, then accessed via Pleasant Valley Road. Early morning and late evening visits offer the best chances to observe wildlife in their natural patterns.

The refuge occupies a valley floor at about 1,074 metres, with slopes rising to roughly 1,420 metres within a couple of kilometres. It lies near Marion, about 19 km to the west, and the surrounding land is forested. The site is not permanently staffed and has few improvements, so visitors should expect basic, undeveloped conditions.