So.. duck mounds, juniper trees, etc... Most of you feel these circles are completely natural?

There have been sightings of similar circles just north of Mt. Shasta at a rest stop that appear to be of an artificial origin. Please see:
Mound Formations near Mt. Shasta
The circular features appear almost identical in size to the circles in the Modoc National forest. There are reports of a sign at a rest stop nearby that concludes the circles are of ancient man made origins.

The rock art in the Modoc forest appears to show circular patterns that suggest these circles could be more than natural features, plus they are not far from the Mt. Shasta circles of unknown origin.



You never really truly know unless you go.