The Devils River minnow (Dionda diaboli) has a limited distribution in Texas and Mexico. It is listed as threatened in the United States and endangered in Mexico. Recent collections in previously inaccessible locations in the headwaters of Pinto Creek, Kinney County, Texas, revealed a large population of D. diaboli. This species was found in habitats of flowing, spring-fed waters over gravel-cobble substrates, usually associated with aquatic macrophytes, but was confined to the upper segment of the creek. The confined distribution of Devils River minnow can offer valuable insight into its habitat and conservation. The future of this population might be threatened by reduced spring flows resulting from excessive pumping from the associated aquifer.