Mount Jumbo is one of two fulsome Missoula hills—the other being Mount Sentinel—that frame Hellgate Canyon, by which the Clark Fork river enters Missoula's juncture of five valleys. Jumbo is the one on the left as you face upstream, to the northeast of downtown. East Missoula lies on the other side of Jumbo.
Jumbo's etymology goes back to the Salish tribe who called the hill—with an elevation of 4,768 feet, it's hardly a mountain by Montana standards—"Sin Min Koos," which more or less means "thing that's in the way." Settlers from the east eventually decided that the bulge looked like a reclining elephant, and "Elephant Hill" served as a name until miners christened a nearby copper lode "Jumbo" after Barnum & Bailey's biggest contemporary draw, and "Elephant Hill" eventually ceded to "Mount Jumbo."
The hill's history goes back even further, past the periodic drainings of Glacial Lake Missoula that occurred between 15,000 and 13,000 years ago, leaving behind the uncannily horizontal relic shorelines that still stripe Jumbo and Sentinel both, in the right light, or first snow.
Jumbo is one of Missoula's defining icons not only in its looming physicality, but by virtue of its purposeful emptiness. An Open Space bond in 1995 combined with contributions from the Five Valleys Land Trust, Montana Fish, Wildlife & Parks, the Lolo National Forest, and the Rocky Mountain Elk Foundation supported a public purchase of Mount Jumbo that now amounts to 1,800 acres of preserved and protected hillface, making it a cornerstone of Missoula Open Space program.
Elk use Jumbo for winter forage, and the northern flank of Mount Jumbo is closed Dec. 1 until May 1; the southern part is closed Dec. 1 to March 15. Invasive weeds including spotted knapweed, leafy spurge, cheatgrass, sulfur cinquefoil and Dalmatian toadflax are an ongoing maintenance issue. Small herds of sheep seen periodically on Jumbo's steep sides are herded there to eat the weeds. Noninvasive flora and fauna include whitetail deer, mule deer, black bear, mountain lions, red fox, swallowtail butterflies, Blue Grouse, Lazuli Buntings, blue birds, falcons, service berry, hawthorn, ninebark, bluebunch wheatgrass, Ponderosa pine and Douglas fir.
The big white "L" on Jumbo is concrete, and stands for Loyola Sacred Heart Catholic High School. A trail to the L starts at the end of Cherry Street and rises 500 feet over the course of 1.5 miles. The South Trail, also beginning at Cherry Street, climbs the southwest face of Mount Jumbo and then extends east, paralleling interstate 90, before accessing East Missoula. The Lincoln Hills Trailhead accessed via Lincoln Hills Drive leads to the Jumbo Saddle Trail and the Rattlesnake National Recreation Area. Dogs should be on-leash for 300 meters from the trailhead, and under voice command subsequently.
Aside from walking, human recreation on Jumbo includes mountain-biking on two trails (Woods Gulch Loop and Marshall Canyon Loop) and, if you know what you're doing, paragliding from the top. Jumbo periodically burns—oftentimes in the vicinity of fireworks season; be aware of the fire danger.
Mount Jumbo is managed by the city's Mount Jumbo Advisory Committee.