Directions:  From Nederland, head north on ... Turn left (west) on 103 (Eldora Road) to the town of Eldora.  103 becomes Eldorado Street in Eldora.  Park at the corner of Eldorado and Sixth Street.  Please respect private property and avoid parking on the dirt roads in the town and near the trailhead.
The Eldora Valley (also called Happy Valley) west of Nederland is beautiful in the fall.  The Mineral Mountain Trail (Forest Service Road 505) is the perfect way to enjoy this valley.  The trail is aspen lined and looks out over the aspen filled valley and the chain of lakes leading to Barker Reservoir in Nederland.  To the west. the trail provides views of the jagged Indian Peaks.

From the corner of Eldorado and Sixth Street, head up Sixth and turn right on Huron Street (2 blocks from Eldorado).  Look for the House and Garage decorated with Antlers and turn left on the dirt road.  The road will veer to the right and you'll see the small Forest Road 505 sign.  A few minutes up trail from this sign, there is a National Forest map and information kiosk, as well as a seasonal gate.  Be forewarned, this road is open to motor vehicles, but it is mostly used by hikers and mountain bikers.

The entire Mineral Mountain Trail travels about 5 miles to the Caribou historic townsite but if you are looking for a shorter hike, the first switchback is a good destination.  The views of the valley are wonderful and get better and better as you gain elevation.  As you approach the switchback the views open up to the east and you are treated to views of Nederland, Baker Reservoir, and Golden Gate Canyon State Park to the south.  The aspen, cottonwood, and other fall colors are tremendous in this area.  

At the switchback the trail gains elevation and passes by a scenic seasonal pond.  This peaceful spot is another great turnaround point, but if you continue for another 1/4 mile or so, you will arrive at the forested top of Eldorado Mountain (confusing since this is the Mineral Mountain Trail).  

However far you decide to go, you will not be disappointed with the fall colors.  The Nederland/Eldora area is extremely busy during the fall peak weekends but this seldom visited trail is an excellent option if you want to avoid the crowds at the Hessie Trailhead just up the road from Eldora.