We just finished a grooming run up White River. (12/24/15) This trail begins near Soldier Summit on Hwy 6. Although the trailhead only has around a foot of snow we found that the snow gets deep quick as you climb up the mountain. We found well over three feet of snow as a general with some areas around four feet.
We plan on grooming North Skyline trail on Christmas afternoon.
Utah Snowmobile Association