Took the tour boat up. Headed to the Bridge and talked with a ranger. We distracted the crowd and headed upcanyon (with the ranger's blessing) to Echo Camp. Brian had never been there before, but Megan and myself had, so this side trip was our idea. We poked around the camp (lots of frogs!) and then booked it back down to the boat. We made it back with literally one minute to spare. Phew!
The Bridge is visible from the boat at the dock, and water is almost under the Bridge. Maybe 5-10 feet more rise in the lake and it'd be under there.