Only open April to October, weather permitting.
The trail starts off on the left side of the parking lot. The start of the trail is wide as you rip down a loose rocky section. The trail will quickly kick up and you'll climb through the pine and aspen forest on packed trails. After a mile, you should be able to make out a faint trail jutting off to the left. Don't miss this one, as it takes you out to a great vantage point that overlooks the valley to the west. From here you can see the Catalina Mountains, the Rincon Mountains, and even all the way to Boboquivari and Kitt Peak 100 miles away.
After soaking it all in, continue on the climb. After another half a mile, the trail comes to a T. Take the trail to the left. Again the trail widens for a little bit and gets a little rockier and continues to go up. After a little less than a mile more, the downhill fun starts. Don't miss the sharp left turn that will take you down some fun switchbacks. Keep cruising downhill, but not too fast or you may miss the raspberries that grow on the side of the trail in the summer. The Grant Hill Trail ends on a slight uphill after a tiny creek crossing.