From its intersection with Gurley Street, travel south on Mt. Vernon Avenue for 6.4 miles as it becomes Senator Highway and passes through the community of Groom Creek. The trailhead is on the left-hand side of the road and is well signed.
Groom Creek Loop Trail #307 is a beautiful trail in Prescott National Forest, and makes fora great ride through the forested high country. This trail climbs to the top of Spruce Mountain. A picnic area, a vault toilet, and a lookout tower are located at the top. When it is staffed in the summer months, the lookout tower when it is open to the public and offers stunning views.
From an MTB standpoint do this loop clockwise to get the most of the downhill section. The uphill part is steep, loose with water bar switch backs in places. A bit of hike-a-bike will be in order. After the summit the fun starts but be careful as the trail is loose in spots and equestrians love the area.