The main vent on the north end of the fissure created a lava tube system.

Several older hills and higher areas were completely surrounded by the flows to form kipukas.

The distal ends of the flows show excellent examples of inflated lava.

It is certainly older than the formation of Crater Lake as ash from the eruption of Mount Mazama overlays the Devils Garden lava flows.

[4] This article incorporates public domain material from Deschutes & Ochoco National Forests - Crooked River National Grassland – Oregon Volcanoes.