Updated description 7/7/14:
The brand-new section of the Cottonwood Trail begins at the parking lot at the junction of CR 175 and 181. From there, this brand-new singletrack rolls across the hillside, with flowy corners and swooping, gradual climbs and descents. It then junctions with FS 173. Take a right on 173, and then in a mile or so a left off the road to drop into the classic Cottonwood Trail in the Cottonwood Drainage. The trail follows the drainage all the way down into the Arkansas Hills Trail System, which then affords several different options to finish the descent into the town of Salida.
While the trail across the top is pretty easy, the descent--especially through the narrow-sided "waterfall" area in the canyon--is technical, with a few very large, challenging features.
This is a great shuttle run close to town, or is a great ~20 mile loop from town.