A few nice gov auctions images I found:
Wild Burros - Lake Pleasant
Image by Al_HikesAZ
Does my ass look big in this?
I went hiking in the Lake Pleasant Regional Park and saw these wild burros
The Spanish brought donkeys, called burros in Spanish, to North America, where they were prized for their hardiness in arid country and became the beast of burden of choice by early prospectors in the Southwest United States. In the western United States the word "burro" is often used