During the uranium boom of the mid-1950's, some 192 tons of low-grade ore were produced at the Morale mine in the Hopi Buttes area of Navajo County, Arizona (Figure 1). The host rocks for the orebody were lacustrine sediments of late Miocene to early Pliocene age in the Seth-La-Kai maar. This feature has been referred to in the past as a diatreme (Lowell, 1956; Wenrich and Mascarenas, 1982a,b; Wenrich-Verbeek and others, 1982). It is herein referred to as a maar because the uranium-bearing sedimentary rocks were deposited within a crater (maar), and the volcanic neck (diatreme) is not actually exposed, but is inferred to underlie the maar. The purpose of this report is to provide an overview of the geology of uranium deposits in the Hopi Buttes area and to publish complete production statistics for the Morale mine (a previous report [Shoemaker and others, 1962] published only partial statistics). Production data were obtained while the author was employed by the U.S. Atomic Energy Commission (AEC) as a geologist on the Navajo Indian Reservation.