this month's WITW challenge, which was won by Oregon geoblogger Lockwood. The three circular features in the photo shown above, taken on a northbound flight from Reno to Seattle, are Big Hole, Hole-in-the-Ground, and Fort Rock. As noted by Lockwood, Big Hole and Hole-in-the-Ground are maars, and Fort Rock is a tuff ring.
You can read more about Hole-in-the-Ground here and here at Lockwood's Outside the Interzone, and about Fort Rock here and in several other posts (and see this compilation for all his 2013 Geo 365 posts, which cover many other locations in the area and elsewhere). Also, this USGS field trip guide is excellent for taking along on any road trips into the area.
View Bend OR to Winnemucca NV in a larger map
I've added the locations of the three features to an earlier map of mine. As you can see, they form a nearly straight line.