My friend and I were at GNP the weekend of Fourth of July, and the float down the river was our chill activity. We enjoyed the cold waters of Middle Fork river, and our guide Cash taught us a little about how to read the river/currents and how to row/turn the raft. We were allowed to jump into the water at certain (safe) points and took a break on a little island-like mass of rocks and old bushes where the folks doing the dinner tour stopped for their river bank dinner. The water was perfect under the hot, blazing sun.
Overall would recommend! Next time I want to try the white water rafting or the raft float dinner tour with Great Northern. :)