Well worth a visit! Afterward you can drop down to Steilacoom. See the old ex-NP depot and watch a few trains by the ferry dock.
To be clear, I am talking about the Lewis Army Museum, down by the Dupont gate to the post. There is or was also a small National Guard museum up by the Camp Murray admin bldg.
The first time I was at Polk was November-December 1970 in AIT for mortar's. The second time June-September 1971 I was an assistant Drill Sergeant. Then off to a vacation in Southeast Asia. I never had time or transportation to explore the bass or area. I only got use of a car to go to Beaumont, TX and came back married and with a new daughter. I wasn't into model trains yet.