Saint Vrain Mountain Trail

Saint Vrain Mountain Trail is an about 8.5-mile out-and-back from its Forest Service trailhead to a rounded 12,162-foot summit. It climbs from forest into tundra, crosses a short stretch of Rocky Mountain National Park, then leaves the maintained #915 for a separate, unmaintained summit route. Allow six to seven hours and roughly 3,200 feet of gain. If the steep, cairn-led talus finish isn't for you, turning around after the open saddle still gives you the Wild Basin view.

The route starts on an old road, then follows a creek up the valley's north side through lodgepole pine and aspen. A sparse stretch of limber pine gives way to steep switchbacks through spruce. The trail clears treeline around 2.65 miles in, where the grade eases and the route opens onto high tundra. The trailhead is already about 8,900 feet up, so the steady climb asks more than the mileage alone suggests.

Above treeline, the trail crosses a broad tundra saddle between Meadow Mountain and Saint Vrain Mountain. For about half a mile it enters Rocky Mountain National Park and levels out with views into Wild Basin: Mount Copeland, Ouzel Peak, Mahana Peak, Longs Peak and Mount Meeker. The route leaves the park again around 3.6 miles from the trailhead. This stretch is a worthwhile turnaround if you want the open views without the summit push.

Near the high point of the maintained trail, watch for an unsigned turnoff marked by small cairns. Sources put it around 3.6 to 3.9 miles from the trailhead, so use the terrain and cairns rather than relying on an exact mileage. The maintained #915 continues south toward Buchanan Pass; the summit route branches away, follows the Indian Peaks side of the boundary posts, and climbs through krummholz and rugged talus. The last roughly 0.75 mile is steep and unmaintained, with snowfields that can linger. The rounded summit has two wind shelters and broad views across the Divide.

From Allenspark, take Boulder County Road 107 (Ski Road) south for 1.5 miles, then turn right onto National Forest System Road 116.1 and go 0.5 mile up to the trailhead. The lot holds about 12 vehicles and has no restroom, so an early start helps on busy days. The route crosses a section of Rocky Mountain National Park where dogs are prohibited; pets cannot complete this route. Organized groups need a free day-hiking permit year-round, and overnight trips require a permit from June 1 through September 15.