Mossyrock | Mayfield Lake Real Estate View 35 listings HomeGuidesMossyrock | Mayfield Lake Mossyrock, WA is a city in “The Heart of Lewis County.” The dams at Riffe Lake and Mayfield Lake make the area a boating and fishing recreation playground. Lakeside properties are highly desirable. Guides PACKWOODAshford | Elbe | MineralEatonvilleMorton | GlenomaMossyrock | Mayfield LakeRandle