We were at the end of our thirteenth and starting the fourteenth day of our journey into the Great Unknown, a rafting trip down the Colorado River from Lees Ferry to Diamond Creek. I had taken an involuntary swim through Lava Falls Rapid that afternoon, but with the swim having been a far less terrifying experience than the first flip back at Crystal, I was feeling okay. Passing through Lava Falls represents to many the climax of the trip, and the last two or three days are sort of a winding down of the journey, with few large rapids.
The collapse of a 1,500 foot tall lava dam may have produced a flood of 15 million cubic feet per second. That's more than 30 times larger than the biggest flood ever recorded on the Mississippi River. That's how you move 115 foot boulders.