A recent Men's Journal article, "Native American Tribes Embrace Tourism," explains how tribes around the country are branching out into the tourism industry to diversify their economies, educate outsiders, and reclaim their public images.
The article specifically mentions two Native-owned tour companies:
Monument Valley Simpson's Trailhandler Tours
Diné (Navajo) tour guides provide a variety of trips (Jeep tours, hiking tours, and photography tours) in the Monument Valley, Utah.
An award-winning ethical travel company offering tours in the Great Plains and the Southwest (South Dakota, Montana, Wyoming, Nebraska, Arizona, Utah, Alaska) with a vast array of types of tours at various price points.