Mayfield Dam serves nearly 58,000 homes each year. The hydroelectric dam, completed in 1963, includes a 250-foot-high (above bedrock), 850-foot-long, concrete arch and gravity dam that forms Mayfield Lake.

In addition to the Cowlitz River, water from the Tilton River also contributes to Mayfield Lake.

The 2,250-acre lake is formed by the Mayfield Dam and offers year-round recreation. The elevation of the lake fluctuates no more than 10 feet throughout the year. Public boat ramps and campgrounds are located at Mayfield Lake Park and Ike Kinswa State Park. Several privately run recreational areas operate with permits from Tacoma Power.