Thirty-six test holes were augered by the U.S. Geological Survey in the vicinity of Soldier Creek, Rosebud Indian Reservation, Todd County, South Dakota. Wells producing more than 5 gallons per minute (0.32 liter per second) from the Tertiary deposits are rare. However, as much as 20 feet (6.1 meters) of permeable alluvial deposits were penetrated in several test holes. One test well was pumped for 2 hours at a rate of 10 gallons per minute (0.63 liter per second)