Please look carefully at the Google Earth screencaps I have uploaded.
These go with the drop-site theory I began on page 28.....
This seems very possible.
Perp does a DAYTIME drop from a boat, because putting out at night could attract more attention with the lights.
He puts in at Butte La Rose... goes upstream and loops around to Whiskey Bay from the back, so as to get to the Pilot Channel branch and access that deep water flowing south.
Pilot_Channel_1
After he hits the channel, there are camps on the left bank, so he can't risk being seen.
Pilot_Channel_2
He passes the last camp just far enough to be out of possible sight... far enough from the bridge where no one can see what he's doing... throws in a weighted bag..... and then the bike. He sees the bike sink, but forgot about the inflated front tire. He thinks he's done, and in the clear, turns around and heads back to Butte La Rose.
Meanwhile, the bike bobs along a bit under the surface.... follows the current... as the channel bends, it drifts more and more to the left, following its momentum. Finally, the bike comes to rest near the bottom of the bridge, along with all the other trash that the bend has collected... to be later found lying just off the bank and mostly submerged....by the fisherman.
Drop_Site
That puts the capper on my theory I developed beginning on Page 28.
Please view the links!