Arizona is one of the best places in the US for stargazing thanks to its clear desert skies, mountainous geography, and plenty of rural areas that aren't affected by light pollution. Oracle State Park is only 20 miles south of Tucson, but the skies are shielded from the city lights by the Santa Catalina Mountains. It's a designated Dark Sky Park, which makes it your best bet for epic stargazing without having to venture too far.
Another top spot is Organ Pipe Cactus National Monument, which has an awesome campground set in the lush desert, perfect for a night of watching the sky light up. Plus, the area is home to one of the state's best hikes.