Beach Drive (right down Rock Creek Park) is closed to cars on weekends & holidays from the DC line to where it picks up the bike path by the zoo.
Here's what I was planning on doing next Saturday:
- Crystal City to Bethesday (~12 Miles)
- Bethesda to Nats Park (~13 Miles)
- Nats Park to Crystal City (6 Miles)
Total: 30 miles, should take around 3 hours plus a lunch break.