Bolam Pass  
USGS 7.5' Map: Hermosa Peak, Engineer Mountain, Mount Wilson
Difficulty: Number: Miles: Altitude: Obstacles: Time:
Easy 2 FR578 19.20 8,790 to 11,430 ft. NA 3-4 hours
County: San Juan, La Plata, Dolores
Adopted by:      
Managed by: San Juan National Forest,
Columbine Ranger District
San Juan National Forest,
Dolores Ranger District
367 S. Pearl St., Bayfield, CO 81122

29211 Highway 184, Dolores, CO 81323

Summary: Bolam Pass is a connection road from Hwy145 north of Rico, through the Hermosa Creek drainage, over to Hwy550 north of Durango.
Attractions: Scenery, Mining, Trailheads, Camping
Dolores District side, Natural - Closed by heavy snows.
Columbine District side, Natural - Closed by heavy snows.
Best Time: June - Late after spring snow melt
July - Best, may still have snow
August - Best
September - Best
October - May be snowed closed
Trail Heads
Colorado Trail - Hike, Mountain Bike, Equestrian
Hermosa Creek Trail, FT514 - Hike, Mountain Bike, Motorcycle, ATV
East Fork Trail, FT638 - Hike, Motorcycle, Equestrian
Camping: There is a Forest Service campground, Sig Creek, on the east side in Hermosa Park East, as well as dispresed campsites along Hermosa Creek. There is also the Upper Hermosa campground near the Hermosa Creek Trail trailhead. On the west side near Hwy145 is the Cayton campground.
Base Camp: This would be a good area to base camp to explore the 4WD roads around Hermosa Creek.
Fall Colors: Very Good - Aspen groves along Hermosa Creek, with smaller groves along Barlow Creek.
Navigation: From Durango, CO head north on Camino Del Rio toward W College Drive for 0.7 miles. Continue onto US-550 N/N Main Ave. Continue to follow US-550 N for 26.1 miles. Turn left onto Purgatory Blvd and go 0.5 miles. Turn right onto Forest Road 578 and start the Bolam Pass road.

From Dolores, CO head east on CO-145 N/Railroad Ave toward Breanna Lane. Continue to follow CO-145 N for 42.7 miles. Turn right onto County Road/FR578 and start the Bolam Pass road.
History: The Graysill mines were a product of the uranium minning era in the 1940s. In 1945 the mine was discovered as a source of vanadium and uranium. Vanadium was useful as an alloy for hardening steel. Uranium's radioactive properties were used to produce atomic power. The U.S. goverment created the Atomic Energy Commission to encourage uranium porduction and the "rush" was on! By 1947 four tunnels had been developed, five more were added by 1949. The mining was done by the room-and-pillar method. The ore was shipped to Vanadium Company of America's reduction plant in Naturita, CO. Later it was shipped to the Durango reduction plant. At its peak, the Greysill area supported 450 working claims, but shipped only about 3,000 tons of ore a year. The mill separated "red cake" (vanadium) from "yellow cake" (uranium). Some of the Durango yellow cake was used in the development of the first atomic bomb. Miners in the rugged San Juan Mountains always faced harsh living conditions, but this "modern mining" added a new danger, odorless, tastless, radioactive radon gas. Only a scant 20 men endured the bitter winters and radon gas risks to mine here throughout the year. The mine operated from 1945 to 1963.

Forest Service sign
After leaving the Purgatory Ski Resort parking lot, the Bolam Pass road will head north through the aspen forest. You will come to a switch back that heads you back to the ski resort as you climb the ridge. The road will loop around and climb up six switchbacks following a branch of Purgatory Creek. The road will remain a graded two lane road as it crosses a low saddle into the valley of the East Fork of Hermosa Creek. Here you will come to an intersection, with the left being the Elbert Creek, FR581, road that heads south up into the Purgatory ski runs. Take the right to continue on the Bolam Pass road. You will climb up a low ridge and head north to an intersection with the Cascade Divide, FR579, road to the right. Stay to the left here. You will now drop down along the north side of the East Fork of Hermosa Creek. You will come into a long wide valley and come to another intersection. The left turn is the Purgatory, FR772, road, which goes about a half mile across the valley. It gives access to some dispersed camp sites and the lower end of more ski runs. Stay right, or straight, heading west along the valley. You will come to a short pulloff on the left side of the road which gives you a view of the old Harris Ranch. Continuing along the road you will quickly come to another small pulloff west of the Harris Ranch.

The road will continue west along the valley as it begins to narrow. Where the valley seems to end as the forest closes in you will come to the Sig Creek Campground entrance on your right. To the left are two short spur roads to campsites. Just past these are two more spur roads to campsites along a rocky ledge above the creek. The valley will open up a bit as you pass more spur roads to other dispersed campsites. The next major intersection is with the Upper Hermosa Creek campground and Hermosa Creek trailhead to your left. Staying to the right you will begin to head north as you enter into Hermosa Park, the wide open area where the East Fork of Hermosa Creek enters into Hermosa Creek. The canyon for Hermosa Creek will be much narrower as you run along the east side of the creek. The road will head north as it passes a few pulloffs for access to the creek. Next you will come to a wide crossing of Hermosa Creek and then pass another dispersed campsite along the road. After making a hairpin turn you will come to another intersection. The road on the left climbs up Hotel Draw, it is the Scotch Creek Pass, FR550, road. Stay to right to stay on the Bolam Pass road. The road will become a wide two track from here as it continues following Hermosa Creek.

The road will climb up this wider valley through the more open patches of forest. You will pass some short spur roads that go to dispersed campsites along the creek. The road will become more of a ledge road as you continue up the valley. You will pass an avalanche chute off of Hermosa Peak as you go. Just past the avalanche chute you will do two switchbacks, then you will come to a series of ten switchbacks which climb to the top of the shear head wall of the valley. At the top of the ridge is the Graysill Mine, which has a few buildings still remaining.
Graysill Mine (1993)

photo by:
Adam M

Past the Graysill Mine the road will loop back west and pass a small lake. At the lake is a large pulloff marking where the Colorado Trail crosses the road. As you come to the end of the lake there will be another intersection, with FR578.B heading off to the right. This road is about two miles long, ending in Tin Can Basin near the East Fork Trail, FT638.

Staying to the left, or straight, you will be facing the shear wall of a mesa off the east side of Hermosa Peak. The road will make a switchback and then climb around the east side of the mesa. Just past a treeless slope as you head north is where you cross Bolam Pass (more accurately, the pass is below the road in the flat meadow at the south end of Tin Can Basin). Continue around the mesa to a wide pulloff on the right side of the road. Here you will be at the top of a large scree slope with views down into Tin Can Basin, the headwaters of the Dolores River, and across to Sheep Mountain, the San Miguel Mountains, and Flattop Mountain to your left. The road will continue around the mesa, heading west. You will pass a short spur road on the right that goes to a small campsite. At over 11,300 feet, it will make for a cold night camping here. Next you will pass a spur road on the left that goes to a small cabin. Continuing on the main road you will come out into the more open top of the mesa. The next intersection is with an illegal short cut to the left. Continuing a short distance you will come to a T intersection. The road to the left is FR149, which only goes about a half mile to a parking area that is a trailhead for the Colorado Trail. The parking area is on the north side of Hermosa Peak just shy of the large scree slope from the top of the peak. Take the right to stay on the Bolam Pass road.

Just past the intersection you will pass a large rough cut in the mesa on the right. This is the very start of the Dolores River. The road will continue on passing through a series of large open meadows. Finally you will come to two switchbacks which start your decent into the Barlow Creek valley. Just past the second switchback you will cross a large scree slope as you head into the valley. As you get closer to the valley floor you will come to an intersection with a spur road to the left that goes down to a campsite. The main road will continue west and pass a small cabin as it approaches the creek. The road will stay above the creek as it crosses the side of Flattop Mountain. There will be open meadows below aspen groves as you head down valley. The road will cross Barlow Creek and then come to an intersection. The left turn is FR496, which climbs a series of switchbacks up the lower part of Telescope Mountain. It will end in an area that was thinned in the past. The main road will be to the right, or straight, as it continues to follow Barlow Creek. You will pass a campsite on the left and then where the valley narrows you will come to a small marshy pond called Barlow Lake.

The road will be above the creek in the forest as it heads down this narrower part of the valley below Flattop Mountain. You will continue to head north, then come out into the Dolores River valley where Hwy145 is. Where the valley opens up you will come to an intersection with the road to the right going to the Cayton campground. Stay to the left to head out to Hwy145 passing a large parking area near the highway. At the highway, a left will take you to Rico, a right to Telluride.
Data updated - September 29, 2022      4WD Road driven - September 1, 1991      Copyright - 2000-2022