Theodore Roosevelt National Park, North Dakota
The wild horses living in the Theodore Roosevelt National Park bear more resemblance to horses you'd see in a Russell or Remington painting than today's equines. The park's horses tend to be large-headed, short-backed, and well-built. Many are roans, with white patches on their sides—a pattern called an apron that isn't often seen in modern horses. In the summer, the horses can frequently be found grazing along the park boundary from Interstate 94. Elevated points like Painted Canyon Overlook and Buck Hill offer good viewing opportunities.
Pryor Mountain Mustangs, Wyoming and Montana
As verified by DNA analysis, the Pryor Mountain Mustangs descended from Colonial Spanish Horses brought to the Americas by the conquistadors in the 1500s. They also have the distinction of being the only mustang herd remaining in Montana. Most of the Pryor Mountain horses live on East Pryor Mountain, where they are relatively easy to find. The horses living on the range's desert lowlands can be seen along Highway 37 in Bighorn Canyon National Recreation Area. It's well worth your time to pay a visit to the Pryor Mountain Wild Mustang Center in Lovell, Wyo. There you can learn about the herd's most recent location and where you're most likely to find them.
Virginia Range Herd, Nevada
The free-roaming horses of Nevada's Virginia Range became some of the first wild horses in the country to be protected when animal activist "Wild Horse" Annie pushed through a bill that prohibited the poisoning of water holes and roundup by aircraft. The bands tend to be found around watering holes east of Reno. Hiking trails offer the best access, but motorists might catch a glimpse of the herd along Route 341.
Little Book Cliffs Wild Horse Area, Colorado
The area's 36,000 acres of plateaus and canyons are home to 80–150 horses, some of which carry the genetics of Indian ponies owned by the Utes who lived in the area. Because of the rugged landscape, the best way to access the herd is by biking, horseback, or hiking trails. In the warmer months, the bands stick to higher country; the Indian Park and North Soda areas offer good viewing in the summer. In the winter, the horses move to lower ground where there is less snow; try your luck in Coal Canyon or Main Canyon.
Lovers of longears should put this living ghost town on their bucket list! In 1915, miners struck gold in the area, and Oatman quickly became a populous mining town. Along with the prospectors came their burros, used for hauling water and supplies. As the mines dried up, miners moved on, many releasing their donkeys into the surrounding hills. Today, the feral descendants of those burros can often be found wandering around the town, where they con tourists into giving them treats.