Mackenzie Reservoir, on State Highway 207 in western Briscoe County and eastern Swisher County, was impounded in the 1970s when a dam was completed in south Tule Creek canyon. In 1965 the Mackenzie Municipal Water Authority was approved by the state legislature for the purpose of building a dam to provide water for the cities of Silverton, Tulia, Floydada, and Lockney. Clayton Keller of Tulia was made business manager, and a contract was awarded to the Gilvin-Terrell Construction firm of Amarillo. In 1972 the project was begun, just east of the site of the slaughter of the Indian ponies by Col. Ranald S. Mackenzie's Fourth Cavalry in 1874. During construction, archeologists from West Texas State University (later West Texas A&M University) explored the lakesite under an emergency grant from the office of Governor Dolph Briscoe. They excavated more than seventy sites where humans had lived 10,000 years ago. In 1974 the dam was finished at a cost of $2,600,000. It is 2,300 feet long, 20 feet thick at the top, and rises 166 feet over the riverbed. At the time of its construction it was the tallest earthen dam in the country not built by federal funds. The wetted and rolled embankment contains 3,657,000 cubic feet. The dam has three outlets: a thirty-inch pipe to connect and service the four cities; a sprinkler system; and an eighteen-inch pipe to release water downstream when the Texas Water Rights Commission (later the Texas Water Commission), which granted approval for the dam's construction, so requests. In the early 1990s the lake had a conservation surface area of 910 acres and a storage capacity of 46,250 acre-feet at the service spillway and some 56,000 at the emergency spillway. In May 1976 a 2,386-acre park owned by the Mackenzie Municipal Water Authority was opened to the public for fishing and camping. Several boat ramps, campsites, and hookups were provided in the park, which was run by a concessionaire. In addition, several lots were leased for lakeside homes. In the 1990s the lake was still a popular site for camping, swimming, picnicking, and fishing. The only quartz quarry in this part of the United States is near the reservoir.