Have to say AZ as well provided it has been garage kept. Otherwise the interior will be faded, the dashboard cracked, and the paint beyond salvage (if it's older than about 4-7 years).
Southern/ mid Missouri. I bought 2009 and 2011 trucks both from the middle of Missouri. They both had around 190,000 to 200,000 miles on them. Super clean trucks. Here in iowa stuff gets rusty quick but the further south you go in to Missouri the less it snows. Any they don't use salt. Missouri vehicles won't have the sun fading issues like from the southwest either. Prices are good too. I used Facebook marketplace for both. Back in 2017 I Paid $10,000 for the 09 3500hd 4x4 with the ion alloy wheels and in 2018 I paid $13,000 for the 2011 2500hd 4x4. In both cases I got reliable clean trucks. And For half of their book price. I still have both today.
