Not Navajo. Often a stone circle is the foundation of a traditional hogan, but this is in the wrong place–over a lava field, no grazing near–and the “doorway” break faces west, not east.

Puebloan? There are tumbled Ancestral Puebloan structures in the neighborhood, but they’re all square-cornered. Nor can it be a kiva, because it was built right on the sandstone slabs.

The fallen ponderosa that divides it neatly in half is old, but thick lichen says the circle is much, much older.

What was it?