The Continental Divide National Scenic Trail
Guide for the Montana/Idaho CDNST

Author, Lynna Howard,

"PrueHeart the Wanderer"

Lynna's boots and gloves. Photo courtesy of Leland Howard.

See below for an excerpt from a Sample Chapter

Red Rock Pass to Keg Springs Road

Centennial Mountains Wilderness Study Area
9.74 miles - Difficulty, Moderate

• Review the precautions and safety guidelines for hiking and camping in bear country. This trail is close to lands managed as prime grizzly bear habitat. Both grizzly and black bears may be encountered in the Centennial Mountains.
• Check the status of the bridge over Hell Roaring Creek by calling the BLM Dillon Resource Area office at 406-683-2337. The Creek can be forded at low water but is not passable at high water (about June to mid-July). If the bridge is out, you may have to take the Nemesis Mountain Trail Detour described at the end of this Segment.
• Be aware of avalanche danger in the Spring. The entire northern front of the Centennial Mountains and all of Hell Roaring Canyon are subject to avalanches. One avalanche chute crosses Hell Roaring Creek above the site of the bridge and flows up the other side of the canyon, leaving the creek to tunnel under it. Hikers are tempted to cross on the resultant snow bridge, a practice which is extremely dangerous. DO NOT CROSS ON THE SNOW BRIDGE. Check the route around the base of Nemesis Mountain with binoculars from Red Rock Pass Road. If it looks like it may slide, take the Detour. Avalanche danger diminishes by mid July. Depending on weather conditions, the trail may be impassable in May and June.

This segment of the Continental Divide Trail leads hikers into the rugged Centennial Mountains, an east/west range that forms the border between Idaho and Montana for about forty miles. Hell Roaring Creek is the most distant headwater of the Missouri River. Its waters end up in the gulf of Mexico, some 4200 miles downstream as the kayaker paddles.

Where the trail begins just south of Red Rock Pass, you'll find newly-constructed tread and new CDT signs. This new route places the Trail on public lands so that hikers can avoid walking along Red Rock Pass Road. As the trail skirts the northern base of Nemesis Mountain in scattered trees, there are some open views into the ranch lands of Centennial Valley. From the southwest turn into Hell Roaring Canyon the trail climbs through thick pine, spruce and fir forests with only occasional clearings before it reaches the Blair Lake cirque. If you like to fish, bring your rod and license ­ Blair Lake is famous for it cutthroat trout.

The Trail is narrow, but relatively easy to negotiate, with switchbacks on the steeper slopes. It is suitable for horses or llamas only after the deadfall has been removed each season. Local horsemen offer guided rides to Blair Lake and to Lillian Lake, and their side trails can lead away from the CDT. Keep to the trail marked with wooden CDT signs. South-to-north trekkers will find themselves nonetheless walking south, west, southwest, southeast, and west again following the Continental Divide as it meanders. The "finger" of the Continental Divide that jabs east towards Red Rock Mountain is cut off by this new trail.

On the trail, there is water at the Hell Roaring crossing and at Blair Lake. On Red Rock Road there is water in Cole and Hell Roaring Creeks where they cross the road about a mile west of the Pass.

Drive west/southwest on US-20 14 miles to State Hwy 87. Turn right (northwest) on 87 and continue 5 miles to Road 055. Turn left (southwest) on Road 055 and continue 6 miles to Red Rock Pass Road. Turn right (west) on Red Rock Pass Road and continue 3.5 miles to the Pass. Red Rock Pass is well marked with an elevation sign (7120 feet), Idaho/Montana border, and Forest Service signs. The BLM plans to build a parking area just south of the Pass. In the meantime, there is ample parking and unimproved camping in the northwest corner of the intersection of Red Rock Pass Road and Road 056 on a tree-covered rise. Bring your own water.

Red Rock Pass Trailhead from Macks Inn (southwest of the Divide):
Drive north on US-20 5.5 miles to Road 053. Turn left (west) on Road 053 and continue 7 miles to Red Rock Pass Road. Turn left (south, southwest) to Red Rock Pass Road and continue 3.5 miles west to the Pass.

Follow the new tread and CDT signs south from Red Rock Pass, climbing gently, but steadily for one mile on a trail that closely parallels the geographical Divide. At 1.1 miles the trail crosses Cole Creek and heads west, contouring around the base of Nemesis Mountain. For the next one and a half miles, the trail leads up and down, with 200 to 300 feet elevation changes, and one series of climbing switchbacks before it turns southwest and enters Hell Roaring Canyon.

In the canyon, the Trail follows the left (east) bank of the creek for .4 miles before it crosses at 3.3 miles on a manmade bridge. The bridge has washed out in the past, so it may be there and it may not (see Detour). At 3.5 miles the trail forks. Avoid the left fork that leads to Lillian Lake, turn right and go only a few steps north of the Lillian Lake sign to find the CDT as it continues steeply uphill and almost directly west. (The branch of the trail that continues north is the Nemesis Mountain Trail, which leads back to the Red Rock Pass Road).

For about .9 miles the CDT climbs, via a series of switchbacks, onto the ridge west of Hell Roaring Canyon. At 4.4 miles the trail intersects the Corral Creek Trail which also leads back to the Red Rock Pass Road. Turn left at this intersection and continue along the ridge south/southeast, climbing towards a bare, rocky knoll (7,800 feet).

At about 6.3 miles you will top the knoll and can look back into Hell Roaring Canyon which looks as wild as any wilderness can get. The loop trail to Lillian Lake re-enters the CDT here, coming in from the left (east). Bear right (west) on a trail that climbs steeply, with some switchbacks, for about 3/4 mile before it crests the ridge, at 8200 feet, that overlooks the Blair Lake cirque.

From the ridge, the trail descends through forested slopes to pristine Blair Lake (mile 7.44), which at 8090 feet offers spectacular views of seemingly endless forests and mountains. In the summer the lake is surrounded by fields of wildflowers and is a draw for deer, elk and other wildlife. The Trail crosses the lake's outlet on the northern shore and there are ample and memorable camping spots along the northern edge. You'll wish you could stay forever.

From the Lake's western edge, the trail climbs for 300 feet to a ridge and then intersects a 4WD road (now closed to motorized vehicles) that leads to the Keg Spring Road. About 2.3 miles from the lake the 4WD road turns south onto the unimproved, but easily negotiated Keg Spring Road, a good exit point for a shuttle car or for friends to deliver supplies. From where Keg Spring Road intersects the CDT, it is about one mile south on the road to good water, and five miles to the Yale/Kilgore Road that leads east to US-20 (about 13 miles). The Yale/Kilgore Road is paved for five miles off of US-20 and intersects US-20 at the Elk Creek service station. It also runs westward all the way to I-15 and is the major access road for many trails and 4WD tracks leading into the Centennial Mountains.