A colorized and paper-thin postcard connected to 1973.12.7a-c-d. The front caption at the bottom left reads: “Thumb Butte, Near Prescott”. The postcard is unused, and the publisher is unknown. Jessie Bevan Collection.

Thumb Butte formed about 14.8 million years ago and reaches 6,500 feet in height. Though its shape resembles the top of a volcano it’s only a particularly large buildup of volcanic rock.

1973.12.7b