Formed by Tacoma Power’s Mayfield Dam on the Cowlitz River, 13-mile-long Mayfield Lake is the setting for camping, fishing, and a multitude of recreational opportunities, with multiple parks lining its shores.  The best close-up view of the Hydroelectric Dam is accessed from Hwy 12 at Gershick Road at Silver Creek. Drive south to the end of the road and viewpoint at Hydro Lane.