Southwestern U.S.A. (southern California, Nevada): 10 days (29 August–7 September, 2005), funded by the Richard Lounsbery Foundation.  Lorenzo Prendini and Randy Mercurio flew to San Diego, California, and traveled ca. 3,700 km, via the Anza-Borrego and Mojave deserts, to Death Valley National Park, the Amargosa desert (Nevada) and the Sierra Nevada, returning to New York from Oakland, California.  The aim of this trip was to collect tissue samples and morphological vouchers of vaejovid and iurid scorpions for Prendini’s projects on vaejovid phylogeny and DNA barcoding.  The expedition surveyed habitats ranging from Sonoran desert, Mojave desert, Great Basin desert, and chaparral, to oak and pine woodland, at elevations from below sea level (Salton Sea) to > 2,200 m (Ancient Bristlecone Pine Forest).  More than 600 specimens were collected, including 30 scorpion species in nine genera and three families.  Among them were several species endemic to Death Valley and the Sierra Nevada.