Glacier National Park holds more than 150 named mountain peaks, but only six climb above 10,000 feet in elevation. Many a mountaineer has sought to bag each of these high points, and Mount Jackson is often one of the first to be checked off the list due to its central location and impressive stature.
At 10,052 feet, Mount Jackson dominates its place along the Continental Divide in the Lewis Range. The peak’s sheer prominence rises above Gunsight Lake and is surrounded by a stunning display of glacial ice not found anywhere else in Montana. Avid local climber David Steele says that’s a big part of Jackson’s appeal to Glacier mountaineers.
“That area is the most heavily glaciated section in the park,” said Steele, who works at downtown Kalispell’s Rocky Mountain Outfitter.
The park’s largest remaining glacier, Harrison Glacier, lives directly below Jackson’s southeast face. A maze of imposing crevasses wriggle across the sprawling sheet of ice that covers more than 480 acres.
The sizable Blackfoot and Jackson glaciers command the view to the east. Historical photos from 1914 show how the ice features were once singular, but have since receded to create two separate glaciers.
Yet another smaller glacier clings to Jackson’s cold and shaded north face.
Steele also notes that among the park’s half-dozen 10,000-footers, Mount Jackson is considered to be one of the less challenging to climb.
“It’s pretty straightforward and there isn’t a massive approach,” Steele said. “After Mount Siyeh, it’s the most accessible of the 10,000-foot peaks.”
Jackson is visible from Kalispell, adding to its status among locals.
“You can see it from the Flathead from a variety of standpoints — it’s pretty iconic,” Steele said.
According to local outdoor author Blake Passmore, most climbers take two days to climb Jackson, using the Gunsight Lake Campground as a base camp. Some ambitious mountaineers choose to climb the peak in a single push.
“Most people camp, but I just like to bang it out in a day,” said Passmore, who included Mount Jackson in Volume 5 of his “Climb Glacier National Park” series of climbing guides. “But, it’s a big, big day,” he warned.
Distance to the summit is estimated to be around 10 miles from the Jackson Glacier Overlook trailhead off the east side of Going-to-the-Sun Road. Starting from the St. Mary Falls trailhead is another option, but requires a bit more hiking.
The approach along the Gunsight Lake trail is casual and enjoyable with minimal elevation gain. Charred snags from the 2015 Reynolds Fire give way to lush understory and ample opportunities to snack on huckleberries and thimbleberries. The Mirror Pond area is a worthy resting place along St. Mary River, offering climbers their first view of Jackon’s entire prominence.
There are a number of routes up Jackson, but the most common northeast ridge route follows a climber’s trail that veers off from the main Gunsight Pass Trail at the foot of Gunsight Lake just across the swinging footbridge. After about a mile, the steep and rugged trail emerges in the lower Jackson Glacier basin, where the true climbing begins.
Climbers are treated to a pleasant walk through alpine meadows before hitting a steep treadmill of scree- and talus-covered slopes that will test endurance and patience.
The scree finally tops out on a long ridge that leads to the proper summit. Sections of the ridge are rated as Class 3, but exposure is limited if the correct route is followed.
Passmore describes scrambling along the ridge as the most enjoyable aspect of the entire climb.
“Walking along the ridge and trying to figure out the nuances of the route, and looking down at Gunsight Lake and all the glaciers — it’s surreal.”
Gaining the main summit offers a rewarding view in all directions. The turquoise water of Gunsight Lake shimmers some 5,000 feet below. The park’s tallest peak, Mount Cleveland, is easily visible to the north on a clear day, while the park’s second-highest peak, Mt. Stimson dominates to the southeast. Those interested in geology will appreciate the long waves of red argillite and white quartzite that streak across cliffs to the northeast.
Most impressive, though, is the unique view Jackson offers of the Harrison, Jackson and Blackfoot glacier basins.
“Of the all places I’ve been in Glacier, [Jackson] is one of the only places where you can see all of them at once,” Passmore said.
Passmore said it’s a good idea to bring a helmet and trekking poles for the climb.
“It’s pretty hard-packed soil in places and the rocks can get rolling,” he warned.
Climbers should also be ready to suffer, especially those looking to bag the peak in a single day, which takes between 12 and 14 hours roundtrip.
“Jackson is not one for a person’s first climb,” he said. “You need to know how to ‘embrace the suck,’ It’s a big, big day and you want to work your way up to that.”