Plenty of room to roam and get away from people on the western side of Berthoud Pass and also Quanella Pass, both of which are 2 hrs from the front range. You didn't say where in CO you are. Both the ones I listed are about midway on a North South basis but if you are south of the Springs or around Ft Collins they would be farther.
I've taken some good bulls behind Granby Res in the Indian Peaks Wilderness Area which allows no motorized traffic and butts up against RMNP.