The past few years we spent the 4th in the San Juan Islands. This year we went to the islands earlier in the year and spent the 4th right here in Portland. From our marina on the Columbia we headed down river and then up the Willamette to downtown Portland. To get there we had to go under a total of TEN bridges! No wonder Portland is sometimes called the Bridgetown! We were able to clear 8 of the 10 bridges no problem, but the two railroad bridges had to be raised or swung to let us through. 
Steel Bridge opening

Here is a good article  (you can change the state to be more appropriate for you) on how to travel through bridges. The article states that “Bridge tenders can sometimes be a little cranky” and we found this to be true. Apparently we weren’t fast enough for our bridge tender when we were waiting for the swing bridge to open ALL the way. 
When we arrived downtown the festivities were already in full swing and boats were everywhere! We found ourselves a little spot on the outskirts and BBQ-ed our all American meal: ribs, potatoes and corn! During dinner there was a lot of excitement as a boat nearly sank. Lucky for them, the Cost Guard Auxiliary and the fire department had brought their big pumps and were already on site. After spectacular fire works we anchored behind Ross Island for a very restful night.
Hope everyone had a happy Fourth!

Boat is sinking (note the audio portion)