Driving on Highway 89 across the Navajo Nation, you’re likely to see the giant art installations of Chip Thomas painted on abandoned water tanks and trading posts. Thomas, a physician, has lived and worked on the Reservation for more than 30 years. …Driving on Highway 89 across the Navajo Nation, you’re likely to see the giant art installations of Chip Thomas painted on abandoned water tanks and trading posts. Thomas, a physician, has lived and worked on the Reservation for more than 30 years. …