The Lewis Army Museum is the only certified U.S. Army Museum on the West Coast. The Museum preserves and interprets historic artifacts relevant to Camp Lewis, Fort Lewis, and the role that the United States Army has played in the exploration, defense, and development of the Pacific Northwest.

The Lewis Army Museum is temporarily closed due to COVID-19 restrictions but will resume regular service when prudence and policy allow.

The Pacific Northwest Gallery documents the role of the United States Army in developing the Pacific Northwest. Beginning with Lewis and Clark's exploration of the far west and continuing through the American Lake Maneuvers of the early 20th century.

The Lewis Gallery interprets the establishment of Camp Lewis and the history of Fort Lewis over the years.

The museum also features approximately an acre of outdoor exhibits which include a UH-1 "Huey" Helicopter, various experimental vehicle prototypes, and armored vehicles.