Owen J. Larimer 1973 <p>Rapid City, the second largest city in South Dakota, is located at the eastern edge of the Black Hills about 9 miles downstream from Pactola Dam. &nbsp;It is bisected laterally by Rapid Creek, and longitudinally by the eastern flank of the Black Hills. &nbsp;Canyon Lake, a samll recreation reservior having a surface area of 35 to 40 acres, is located near the west city limits on Rapid Creek.&nbsp;</p> <p>The floods of June 9-10, 1972, covered a relatively small area of the eastern hills, extending from Sturgis on the north to Hermosa on the south and the west to Pactola Dam. &nbsp;THe area is mountainous with very steep heavily wooded slopes. &nbsp;Channels are shallow and generally are confined in narrow, winding canyons.</p> application/pdf 10.3133/ha511 en U.S. Geological Survey Flood of June 9-10, 1972, at Rapid City, South Dakota reports