The mygalomorph spider Aphonopelma hentzi (Girard, 1852) (Texas brown tarantula) is a geographically widespread and accessible system for the study of comparative development in spiders. However, remarkably little information is available regarding the timing of egg sac deposition and duration of embryogenesis in this species, a gap that can directly affect the success of field collecting efforts. Here, we describe the habitat, egg sacs, and embryos of A. hentzi in the Comanche National Grasslands of Colorado. We compare the effectiveness of strategies for obtaining adult specimens vs. egg sacs of A. hentzi from burrows. Protocols for rearing, fixation, fluorescent immunohistochemistry, colorimetric in situ hybridization, and imaging of embryos are detailed. Together with forthcoming genomic resources, these data are anticipated to improve understanding of embryogenesis in Mygalomorphae and comparative development of chelicerates more generally.