"This is the brand new section of the Anacostia bike path that will eventually connect the riverwalk trail with the tributary trail system in Bladensburg. It is located at the new wetlands just built as part of the Wilson Bridge mitigation project."
This is on the east side of the river between Bladensburg Balloon History Park and New York Avenue. I was completely unaware they were building the trail. I plan to check it out soon though.