Try up the trail that starts here:
40° 9'32.04"N 105°28'7.64"W
I was up here and had the place to myself.
The trail (217) is for vehicles but not cars!
Trail (105) starts up Hwy 7 (
http://www.traildamage.com/trails/index.php?id=123) and joins 217. I've seen regulat SUV's on 105.