Thanks all for the great info. FWIW, I can see connection from the bike path to the bridge in the Google sat photos, and I estimate very roughly 1.5 miles to get to the District side of the bridge.

ColumbiaPete thanks for bringing that up. I figured since the cherry blossom festival parade is scheduled for Saturday, this would be the peak time, but I see now it's really getting past peak, and a strong storm will do in the remaining flowers. I did find a "cherry blossom webcam" at http://www.nps.gov/cherry/cherry-blossom-web-cam.htm and I'll be really annoyed it they pull power on that if the park service shuts down midnight tomorrow