The Horse Flat Trail in American Fork Canyon starts from the Summit Trailhead, and passes through several meadows, large Aspen groves, and shaded areas before finally reaching the Primrose Overlook. This trail is really well shaded, and is perfect during Fall when all the Aspen trees are changing colors. Temperatures are also cooler in Fall - when the valley can be in the 60s, the top of the Alpine Loop Road can be in the 40s. Keep in mind that the Alpine Loop Road is only open during from late June to the end of October, or whenever the first snow arrives. This trail is great for dogs off leash, and even kids can hike this route.