This once desolate patch of Sonoran desert is now a neighborhood. View the Official Route to the right.
From the trailhead, hike along the main road to the right through private property to the county park boundary, where you must pay a fee of $1 per person. ($2 as of 2011-11-25) Follow the trail to the Dixie mine, clearly marked. This part of the trail is relatively flat but affords fantastic views of Four Peaks and the Superstitions along its entire length. If you don't have time for the summit hike, the hike to the mine and back is lovely, easy, and enjoyable. This section of the trail would provide a good introduction to Sonoran landscape for relatives from out of town.
Once you reach the mine, follow the very large and obvious road to the left and straight up the mountain. The last two miles of this hike are extremely steep, as the road builders decided to charge directly up the mountain rather than bother with those wimpy switch-backs. This is about as steep a trail as I have ever been on...and I felt the burn!
Views from the top of Thompson Peak are of the entire Phoenix metro area (many golf courses down below in Scottsdale), south to the Catalinas, east to the Superstitions, and north to the Mazatzals. The best view is unfortunately of the cell-phone towers and related infrastructure that diminish the peak experience. The least Verizon could do is provide a picnic table or something. Remember to bring a walking stick because the hike back down the steep trail is hard on the knees. It is so steep that if you tumbled you'd probably keep rolling until you ended up in someone's front yard in Fountain Hills.
Return the way you came.