The Mojave poppy bee, Perdita meconis Griswold, is a small fairy bee endemic to the eastern Mojave Desert, known to be associated with the Las Vegas Bearpoppy, Arctomecon californica. Because of the reported decline in populations of P. meconis, it has been targeted for protection under the Endangered Species Act. Here, we present the results of a 3-year study investigating the current distribution and floral preferences of P. meconis in Clark County, Nevada. We found that populations of P. meconis fluctuated dramatically from 2020 to 2022. This area experienced extreme drought conditions during these years, which consequentially affected the populations of this rare bee and its floral resources. Analyses of the pollen collected from P. meconis demonstrated fidelity to Arctomecon californica; over 90% of the pollen extracted from the body of these bees and nearly 100% of the pollen carried on female scopae was from Arctomecon californica, confirming this bee as a pollen specialist. Our data also show that P. meconis likely visits Psorothamnus, perhaps as a nectar source, since A. californica does not produce nectar. These data can aid conservation efforts for the Mojave poppy bee, providing valuable insights on the distribution and floral requirements of this bee that can assist conservation efforts.