Mills Canyon is a sandstone canyon carved by the Canadian River on the western edge of Kiowa National Grasslands. There is a campground in the canyon; there are also a lot of mosquitos in the canyon.

Looking up the canyon to the north, from the road as it descends into the canyon, 22 Sep 06.

Looking across a ravine on the east side of the canyon from the rim, 22 Sep 06.

Looking northwest from the east rim, 22 Sep 06.

Rimrock with Pinus ponderosa and nice cracks, 22 Sep 06. Asplenium septentrionale can be found in the crack.