Because of the way the trap was set, it is highly unlikely the beaver approached it other than between the jaws.
The Corps of Engineers does predict the river stage about three days in advance, but again their predictions are accurate only within about 12 inches. What I have to go by is whether the river is predicted to rise or fall. On rising water, I set the trap as shallow as possible. On falling water, I set the trap elbow deep. (I should note that Ohio law requires me to keep a trap of this size, "in water".) Either way, it's a crap shoot.