After entering the Sheep Mountain Wilderness the Heaton Flat trail continues to follow the ridgeline and reaches over several bumps the Allison Saddle separating the Allison Gulch (with the small Laurel Gulch as a tributary) from the Coldwater Canyon. From the trailhead to the Allison Saddle the trail is moderatly steep. The very steep portion of the hike up Iron Mountain via its southwest ridge starts immediately after the saddle.