California and recreation are synonymous. Shasta Lake, part of a national recreation area, is one of the major outdoor attractions in California and the western United States, recording more than two million visitors annually. The lake boasts 365 miles of shoreline and nearly 30,000 surface acres. Shasta Dam is the second largest dam in mass in the United States. (Grand Coulee on the Columbia River in Washington State is the largest.) Shasta Dam is a curved concrete gravity-type dam with 6.5 million cubic yards of concrete weighing 15 million tons. Construction of the dam started in 1938 and ended in 1945. The dam is 602 feet high, 883 feet thick at the bottom, 30 feet thick at the top, and 3,460 feet long. The face of the dam covers 31 acres, equal to six football fields and their stadiums. The spillway, 487 feet, is the largest manmade waterfall in the world. Three times the height of Niagara Falls. It is 375 feet wide with three drum gates each 110 feet wide, 28 feet tall, and weighing 500 tons each. There are 18 outlets on the face of the dam, each 8 1/2 feet in diameter (large enough to drive a pickup truck through) with a maximum spillage capacity of 186,000 cubic feet per second. Shasta Lake is the largest manmade reservoir in the State of California, with a drainage of 6,665 square miles.