Since fireworks are legal in AZ, where can i go to light them off?

even though fireworks are now legal in AZ, cities including Phoenix and Scottsdale, are prohibiting them. the law indicates that they are legal as long as they are basically on the ground. i am looking for a good location that i can go light some off. i bought a big box of them at Costco the other day. if i cant find a good location, i guess i could look into getting a permit, but there would likely be a fee for a permit. looking for answers...