We loved staying in cabin #5 (last cabin in a row)with a view to St. Mary Lake. Very cozy, quiet and peaceful. The kitchen was very well equipped, nothing missing at all. Bed was comfy and shower, a bit small but ok. Outside is a BBQ. We stayed there in October and didn't use the kayaks or rowing boats but I'm sure it would be fun. Not sure about swimming in the lake, there was lots of weed.
Close to the lake are lounge chairs to relax. Distance to town is not far. I'd recommended it, if you like a relaxing time, surrounded by trees and want a nice view.