Margaret Falls. On the southeast slope, between Cowlitz Park and Cowlitz Glacier. The name was in honor of one of the daughters of E. S. Hall, former Superintendent of the Park.
Marie Falls. On the southeast slope, in the upper waters of Nickel Creek. Origin of name not ascertained.
Marjorie Lakes. Near the north-central boundary of the Park. Origin of name not ascertained.
Marmot Creek. A tributary of Cataract Creek, draining Seattle Park, in the northwestern portion of the Park. The name is for the whistling marmot, so plentiful in that region.
Marsh Lakes. In the southern part of the Park.
Martha Falls. On the southeast slope. The falls were named in honor of the wife of the late Elcaine Longmire, by Ben Longmire, the son.
Martin Peak. On the northwestern boundary of the Park. Origin of name not ascertained.
Mary Belle Falls. On the southeast slope in the upper waters of Nickel Creek. The name was suggested by Superintendent Ethan Allen in honor of one of the daughters of E. S. Hall, former Superintendent of the Park.
Mazama Ridge. On the southern slope of the mountain, beginning at Sluiskin Falls. Named for the Oregon mountain climbing club whose main camp was pitched there in 1905.
Meadow Creek. Near the northwestern boundary of the Park. It rises near Tolmie Peak and was named by Bailey Willis in 1883.