Overview
Decatur Mountain sits on the Great Divide, just south of Argentine Peak.
A mountain of mostly pretty gentle slopes it is hiding a gem below its rugged East Face. Deep blue Shelf Lake, towered by cliffs and snow fields- frozen most of the year.
The grassy summit plateau offers a fabulous view especially to the West and (unlike the Shelf Lake below) sees not too many visitors.
Trailheads
Decatur Mountain can be reached from the following two trailheads
SHELF LAKE TRAIL
Drive west from Denver on Highway 285 to Grant. Turn right on Park County Road 62 (Guanella Pass Road).
Drive 6.6 miles to the turnoff for Geneva Park campground and Duck Creek Picnic Ground.
Follow the turnoff .3 miles to the entrance sign at Geneva Park Campground.
Continue traveling straight 2.8 miles from the sign on Forest Road 119 to reach the Shelf Lake Trailhead.
The dirt road is very bumpy and muddy at spots, but it can be negotiated with a normal passenger car if you take it slow. Several spots along the road where you can park if you do not want/dare to go on any further.
The trailhead is marked with a pile of darkblack ore. No real official parking area, you can park along the road.
Trailhead is very busy in summer!
ARGENTINE PASS
Drive on I 70 West, exit before Eisenhower Tunnel and cross Loveland Pass.
Turn onto Montezuma Road #5 east of Keystone Ski Area and follow it until the T-Junction with road 214.
Take a left onto 214 and continue until the parking lot on the right.
The road is closed to motorized vehicles beyond the parking lot.
Camping
OFFICIAL CAMPSITES - GUANELLA ROAD
GENEVA PARK CAMPGROUND
26 campsites with parking spurs 16-30
camping season: May to early September
Use fee $14.00 per night
BURNING BEAR CAMPGROUND
14 campsites with parking spurs 16-30’
Open year round.
Use fee is $13/$14 per night
WHITESIDE CAMPGROUND
5 campsites for TENT CAMPING ONLY
Open year round
Use fee is $12/$13 per night
Unofficial Campsites
Numerous campsites along the mining road from Guanella Road to Shelf Lake Trail.
Regulations
All routes to Decatur Mountain are within the Arapahoe (West of Divide) and Pike National Forest (East of Divide).
Please
LEAVE NO TRACE
Mountain Condition
Best season for Decatur Mountain is late spring to fall.
The upper basin of Smelter Gulch is prone to avalanche as are the slopes of Peru Creek Valley.
A small herd of mountain goats is calling the area of Decatur Mountain its home.
Please do not disturb the animals and DO NOT FEED THEM!