Boy, I guess the residents of ETS aren't in a play-along mood these days!
While I don't have a good answer to the problem, I think this one has the most promise:
-Use my EDC/PSK to start a good fire at the base of several of the nearby large trees, causing them to fall and provide me a handy improv bridge to the other side.
Not that I think felling a tree with fire is a good approach, but it seems possible to find a tree tall enough and close enough to the river to provide a bridge.
Optimally located in a spot where the fallen tree would span, but not be *in* the river, lest the river take the tree while you are crossing.
The trick then becomes falling a 100' tree semi accurately and semi safely with what you have, which still is a fair quandry.
I suppose it would be *possible* with my RSK, but it would probably take a couple of weeks. :-)
-john