F.R. Twenter originally discovered and collected microvertebrates at House Mountain locality MNA 318 in the late 1950s. He provided these specimens to me in 1985 and they were placed in the MNA collection. I thank W.R. Downs for expertly and painstakingly preparing most of the blocks of matrix and a number of other specimens, and for the use of his screenwashing equipment at the Museum of Northern Arizona, Flagstaff. My wife C.D. Czaplewski ably and cheerfully helped collect fossils and modern owl pellets and data. K.P. Dial, L.L. Jacobs, and R.M. Warner also helped with fieldwork, especially plaster-jacketing and collecting the largest block of fossils amid clouds of biting juniper gnats. K. Davies helped examine and rephotograph field localities in 2007. D. Gillette and J. Gillette provided access to the MNA collection as well as help with rephotographing specimens and hospitality. G.C. Bateman directed me to the largest modern owl pellet accumulation and provided discussion and comments on an earlier version of the manuscript. P. Fisher, R. Burkhalter, and
P.D. Polly kindly advised me about preparing electronic images from my original maps and photographs. I benefited from discussions with, and/or critical readings of, an early version of the manuscript by H.L. Black, D. Elliott, S.D. Emslie, J. Ganey, J.M. Marzluff, J.I. Mead, and T.A. Vaughan. Additional constructive criticism came from
C. Bell, C. Jass and an anonymous reviewer. Finally, this paper is dedicated to the memory of Charles A. Repenning, who helped me in many ways with work on the Verde Formation and other studies that I did as a na´ve young graduate student, like he did so many other students and colleagues. Rep was a teacher, scholar, POW survivor, warrior, and gentleman to the end. Thanks, Rep.