Type: Backcountry or Sidecountry
The road to trailhead is closed in winter.
This is a year 'round Bozeman classic. This gets skied in every month of the year and is more popular a route in the summer than in the winter because of road access.
In winter find a friend with a snowmobile and hitch a ride up the Fairy Lake Road. In summer, drive a high clearance vehicle. Park at the Sac. trailhead and hike the short distance to just below the top of Sacagawea Peak then contour around to Naya Nuki peak.
From Naya Nuki peer over the edge and find the entrance to The Great One Couloir
. A bit of downclimbing is necessary, but nothing a capable individual in good shape can't manage. Find the permanent snowfield in the excellent shaded and directly North-facing couloir, strap in and "drop in, bro"!