The Skull Mesa Ruins and Petroglyphs is a site near Phoenix, Arizona that we haven't visited yet. For turn-by-turn directions to the trailhead your should be able to enter 'Spur Cross TH Parking' into your driving app. From the parking area follow the Spur Cross/Maricopa trail for about 2.2 miles and then go right continuing to follow the Maricopa trail and what is now the Cottonwood Trail #247. After another 2.3 miles there should be a trail on the left that climbs up to Skull Mesa. Once on Skull Mesa it is about 3/4 of a mile to the petroglyphs and another 1.5 miles to the ruins. A lot of this looks like you are on your own finding a suitable route as there doesn't seem to be anything official once you get heading up Skull Mesa from the Cottonwood trail.
Included with this post is the GPS file and map that we plan to use for our first visit. If you don't want to wait for us to get around to it feel free to try the GPS file and map for yourself. With no guarantee, of course, but they most often prove valuable for us.