This area is the local's favorite. Miles and miles of trail, all part of a larger system called Jumbo Mountain. The area has/had private property areas through which the trails go through. The area was in transition from private property to BLM access as the majority of the area was BLM.
Getting TherePaonia/Hotchkiss - You can pretty much Google this nowadays and get there easily. No secrets here. The drive takes about 4 hours from Denver to get to the Paonia/Hotchkiss area.
See map. Large group of trails on the mountain.
MUD. Slippery, sticky, clay mud. Once it is frozen in the fall, you can ride it. Not so much if it is a wet spring.
Galaxy Bike Shop in Paonia is the closest facility for any sort of bike assistance and for maps of the area as well. Revolution Brewing in Paonia, happily across the street from Galaxy Bike Shop, is a bike friendly brewery.
Lots of camping around as well as nice Bed and Breakfasts, like Hanson Mesa Bed and Breakfast, and some not as nice motels. Lots of National Forest around, as well as Crawford State Park and Paonia State Park. Delta County has some great info on lodging and other things to do in the area.