Here's a place you should visit: Oatman, Arizona. It's a quintessential old Western mining town located on Route 66. It's also full of wild burros that are descendants of the burros that were originally used in the mines. When the mines closed, the burros were set free, and now they roam the streets of Oatman during the day and return to the mountains at night.
As Visit Arizona explains:
Nestled in Arizona's rugged and remote wilderness, this tiny town's rich Wild West history comes to life with staged shootouts, wooden sidewalks and a bounty of burros that roam freely. At first glance, the wild burros of Oatman seem to steal the show but dig a bit deeper and you'll discover the town's raucous mining history and a vibrant main street that plays host to various events throughout the year.
Oatman is best known for its beloved burros—small donkeys descended from miners' beasts of burden. The town is home to more burros than people, and it's not unusual to see dozens of donkeys in Oatman wandering the main drag, sticking their heads through the rails along the wood-plank sidewalks, nudging people for treats and otherwise delighting visitors. The burro has become such an integral part of Oatman's identity that the town now plays host to an annual Burro Biscuit Toss, where residents and visitors alike compete to see who can throw a dried-out, gold-painted burro dropping the farthest.
You should definitely make the trek to Oatman to tour the old mines, to have a drink and a burger at the Dollar Bill Bar (built in 1902), to stay at the haunted Oatman Hotel, and to witness the burros that roam the streets freely. But you definitely should NOT feed the wild beasts! As Pin in the Atlas explains:
These are wild animals and really shouldn't be given treats from tourists, especially junk food like chips, hamburgers, hotdogs and popcorn! This food is not only incredibly bad for them as they are grazers, which means THEY DON'T EAT MEAT! (We saw someone feeding one a hotdog! How ignorant!!), but can also make them aggressive.
Fitting in Adventure reiterates this warning to never feed the burros. Not only can you get fined by the BLM (Bureau of Land Management) for feeding the burros, it's also bad for the donkeys:
Please do not feed the burros on the roadways into town. It will teach the animals to come to the road and could result in accidents.