FWS will designate critical habitat, if determined to be prudent and determinable, for two Nevada buckwheat species, the Las Vegas buckwheat and Churchill Narrows buckwheat, under the ESA. The FWS is required to designate critical habitat, to the maximum extent prudent and determinable, concurrent with a listing determination for the species. FWS will develop a listing determination for the two species as a separate rulemaking action (1018-AZ07). The Las Vegas buckwheat is a woody perennial shrub that is found in sparsely vegetated gypsum outcroppings in Clark County and southern Lincoln County, Nevada. The Churchill Narrows buckwheat is a low, loosely branched perennial found in dry, relatively barren and undisturbed soil in the Churchill Narrows area of Lyon County, Nevada.