Do your research before getting into rivers. My local river has several gauges and hotlines you can call to get dam releases. They also have a chart of the water release amounts and if you could paddle/float/canoe/kayak etc. It even has a turbidity gauge that will show you if any harmful bacteria is present, we have issues with fertilizer runoff and e-coli. It's a rather mundane river in an area not as known as Glacier National Park.
>The river was swollen with alpine runoff.
Red flags right immediately.
If you ever hear 3 horns blasts, get out immediately. A dam might release.
I would NOT go down any side forks. Just like the author I have been messed up and thrown off my kayak by downed trees on a fork. Luckily the water was waist deep and I could stand right away.