River is a Track that was going to be added in Bloons TD 5 Mobile, but was never implemented in the game. This Track was mentioned in the description for the update, but Workshop took its place. It is based on a long, curvy river, gradually curving to the top and to the bottom. There's a lot of water, making it a good place for Monkey Buccaneers. There's 1 entrance and 1 exit in this track.
- This track is one of the most water filled tracks in the entire BTD series.
- This is one of four river tracks in the BTD series, the others being River Bed, Snake River, and Downstream.
- This is the first track that was rendered unimplemented.
- This track is similar to the tiles in BMC.