Prior to this study, there was no information on arthropods, bats, and other vertebrates of caves in northwesternmost Arizona. Based on invertebrate and vertebrate inventory work conducted during 2005 and 2006, we provide future directions for conservation and management for caves on Grand Canyon—Parashant National Monument, northwestern Arizona. Baseline investigations to find and identify arthropods, bats, and other vertebrates were conducted at 7 of the largest known caves on the monument. We identified 52 morphospecies including 44 arthropods, 4 bats, and 4 other vertebrates. Of the cave-dwelling arthropods, we found 10 eisodophiles, 6 troglophiles, 8 questionable troglophiles, 7 trogloxenes, 8 accidentals, 3 taxa of unknown cave affiliations, and 2 mammalian parasites. We made several contributions to the entomological record including 2 new genera, 6 new species, 3 possible new species, one range extension, and one possible range extension. Also, we identified 5 bat roosts—1 hibernaculum, 2 night roosts, and 3 summer roosts of unconfirmed use. Observed arthropod richness per cave ranged from 1 to 14 morphospecies, and observed bat and other vertebrate (combined) richness was 1–3 morphospecies. We did not detect any cave-adapted arthropods during this investigation. For the caves sampled, we are uncertain whether the lack of cave-adapted taxa is due to (a) low nutrient input and high cryptoaridity associated with many southwestern cave systems or (b) lack of intensive sampling. Despite the lack of cave-adapted species, 5 of the 7 caves inventoried are considered of high management concern. Additional research at these caves will be required to obtain the data necessary to best manage and protect these systems.