Two soil gas helium surveys were carried out in a section of the McDermitt caldera complex of mineralized volcanic rocks in Oregon. A regional helium anomaly was found and is thought to be associated with uranium-rich tuffaceous fill of the caldera and the Aurora uranium deposit, which occurs near the northeastern rim of the Caldera. Local hydrology may have an effect on the displacement of the helium anomaly from the uranium deposit and be a carrier of helium from sources at depth. This study suggests that helium surveys may be useful in a volcanic environment by helping to select areas for exploratory drilling for uranium deposits.