Several years ago a short tour I took with Grand Adventures (maybe 4 hours?) was slow and rough on the trails, except when they went to a bowl where you are supposed to ride in a circle for an hour or so. Wide experience level, so the group had to go with the least experienced. Would the Snowy Mountain Range in southern WY be an option? I had a much better ride there (and a better price IIRC).
Snowy Range Trail System
A sledder's playground in southeast Wyoming, this trail system features 166 miles of groomed trails and 136 miles of ungroomed, signed trails. Full services are available in Laramie, Saratoga and Rawlins. Limited facilities are available in the mountains. Guided tours/rentals are available in Laramie and on the mountain. Snow depths of 12 feet are possible.
■Services: In Laramie, Saratoga and Rawlins
■Base Elevation 7000
■Top Elevation 11000