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population was not a subspecies of roundtail chub, but rather a "distinctive population" of Virgin River chub. However, since the Moapa population was not included in the original listing for Virgin River chub, it would require a separate ESA determination. Dexter has maintained a refuge population of Virgin River chub since March of 1989. The donor population.consisted of fish primarily from the upper reach of the Virgin River. In this report, we refer to the river within Utah as the upper Virgin River and the reach within Arizona and Nevada as the lower Virgin River. Dexter's original stock included 162 fish collected from the Virgin River near St. George, Utah. In November of 2002, a total of 483 chub were added to the captive stock: 455 from the upper Virgin River, and. 28 from the lower Virgin River. The most recent infusion with wild-caught fish was in November of 2005 when 93 salvaged chub from the upper Virgin River were brought to Dexter. Dexter maintains a minimum of 450 adult fish on an annual basis. In recent years, fish from spawns of the refuge stock at Dexter have been used to supplement wild stocks due to declining numbers in the Virgin River. In March 2006, Dexter provided 4,000 chub to stock near the mouth of the Santa Clara River in the upper reach. In March 2008, an additional 6,408 chub were stocked in the upper reach. Fish for both stockings were the result of hormonally induced pair matings of ten pairs of adult Virgin River chub. Prior to 2006, one stocking had taken place: 1,290 fish, the result of natural pond recruitment, were transferred from Dexter to the upper Virgin River in November 1994. To effectively conserve the species, it is necessary to know whether there is population structure throughout the range of the species. Questions regarding whether the population in the Moapa River is genetically distinct from the Virgin River, and 4