Really nice spot, walked up with my wife and our 2 year old son in the backpack. Talked to the ranger stationed at the lookout and surveyed part of the active Pier Fire currently burning on Black Mountain.
I went on a hike to Mule Peak Lookout using trail 31E43. The trailhead is located about 5 miles off of Western Divide Highway using road 22S03. The altitude is 8142', the elevation gain is around 500 feet, and the distance is approximately 1.5 miles round trip. We found the register on some rocks at the summit near the lookout.
It was well worth the long drive to the trailhead and hike up to the top to see the view! I enjoyed talking with the Lookout about her job. Recently she had a direct lightning strike... this time of year when the monsoonal flow from Mexico causes thunderstorms in the Sierra it's wise to hike to the top of Mule Peak in the morning... don't wait until afternoon!