According to most historical sources, the Salish Indians called the present Mount Jumbo 'Sin Min Koos,' which roughly translates into 'obstacle' or 'thing in the way.' David Thompson called it 'Brown Knowl' when he climbed in on February 26, 1812. Later, eastern settlers thought Mount Jumbo looked like a sleeping elephant and miners christened a nearby copper mine 'Jumbo Lode' in honor of Barnum and Bailey's most famous attraction. Locals saw the landform as a reclining elephant with its rump in the Clark Fork River and its trunk pointing north toward the Rattlesnake Mountains; the round grassy mountain became known as 'Elephant Hill.' Later, the feature was renamed Mount Jumbo.
In 1995, Missoula residents voted to support an open space bond to help purchase Mt Jumbo to protect its unique wildlife habitat and public access. Additional funding and support from Five Valleys Land Trust along with Montana Fish, Wildlife & Parks, the Lolo National Forest and Rocky Mountain Elk Foundation cemented Mt Jumbo as the cornerstone of Missoula's open space parks.