Wish I would of seen this sooner. I lived down in Tucson for 6 years. It has been a decade since i lived down there so I do not know how the hatches have been and I won't mention super specific locations. I mostly hunted without dogs but did make it out with friends pointing dogs a few times.
As you are aware there are three types of quail in Arizona. I mostly hunted Gambel's but successfully harvested all three species.
Gambel's are the most widely distributed and the easiest to find. Generally you are going to find this species in the areas which are dominated by cactus though they do extend into the prairie edge habitat some. They are the best species if you are going to hunt without a dog (i.e. if you dog is recuperating and you are going out anyways). The singles hold a lot tighter than the coveys do. I actually hunted these a lot like I used to hunt big game. If possible get out at first light. This is when they are most vocally active and you can often locate coveys based on their calling. I also used to use a binoculars in order to scan the washes if I gained elevation. My preferred shot and choke was 1-1/8 oz lead #6 with a modified choke. Due to the sparse cover, shooting lanes can be long and recovery is often less complicated. I have killed quail at 50-60 yards with this combo. They call the Gambel's a true desert quail that does not need water. That said, I have found that they will drink from standing water and often orient to it. I suggest doing some e-scouting by looking at satellite imagery for cattle tanks. If there is a cattle tank in a prickly pear forest, I would generally find a covey of Gambel's within about 300 yards of it. Pick the cattle tanks out as your objective and then criss-cross the washes on your way to the tank. You will find quail well away from the tanks, but I always found the highest concentration in proximity to them. If you see a covey running on the ground that is to far for a shot, do everything you can to break the covey up. For me this often meant shooting my gun into the air/at nothing as a way to startle them.
Scaled quail I hunted the least. They are more of a prairie bird and are difficult without a dog, which I mostly did not have. That said if you want to target them head to the southeast part of the state. The Wilcox area will have a mix of Gambel's and scaled quail and heading east to the boarder with New Mexico you will in general start to get more scaled quail. To me it seemed like they would orient a little bit more to the cover in ravines but their location seemed a little random to me. My suggestion is to find the relatively low elevation prairie and set the dog loose.
Mearns quail were made for a pointing dog though you could certainly run a flusher. They hold really tight, they make bobwhite seem like runners. The first mearns that I killed I almost missed because as I was walking into a point I saw one sitting on a fallen tree with no cover and I tried to grab it. It hit my fingers with its wings when it took off.......
To target mearns you will have to head south. The closer to the Mexican boarder the better. They like to dust and eat the tubers of scrub oak. In general you are going to want to be higher in elevation than the scaled quail. The best hunting is in the hills if your knee can handle it. It is not as bad as chukar hunting but it is reminiscent of it.
Bring two things for your dogs getting into cactus, in particular cholla. A needle nose pliers to pull out of feet. To get then out of the fur the best thing in my opinion is a fine tooth metal comb. In general the dogs figure out how to deal with it and avoid cactus after the first day or two.
I am not going to post super specifics on the open internet, but if you are hunting the Tucson area, PM me for details on locations that were good 10 years ago.
