Stay put, stay dry, start a fire.

Fifty feet is no longer "small." Attempting to cross is suicide -- especially in winter.

Friends and I did a loop hike on Mt. Hood (near Lolo Pass) one warm July day -- starting up the mountain in the morning and coming off mid-afternoon. On the way back down we came to a small stream crossing we'd done a few hours earlier (when it was maybe 6 feet across). Using hiking poles, on the way up we had easily stepped across on a log that had been laid for a bridge.

In the intervening hours before we attempted to cross back over, glacial melt had swelled the stream to a deeper, raging, cold torrent. The log was no longer an option and so we waded in - water up to our hips. My dog (Samoyed) wouldn't go so I carried her. I faced upstream for the slow shuffle, stepping gingerly on the submerged river stones to get across, with a very narrow zone of balance keeping me from being swept backward.

That was just a small fraction of what you're talking about traversing and no way in heck I'd do it in winter -- unless the truck was a few feet away already running, heater on full-blast with towels and a change of clothes inside. I'd be hesitant to try that crossing again on a hot summer day.

Fast-flowing water is an incredibly powerful force.