Earlier quoted context omitted.
Wouldn’t it not count as income until you sold it for USD? In which case you wouldn’t be liable for every fork, just the ones you benefitted from.
That's the way it's treated in UK law, but apparently in the US, you're liable for the tax as soon as you have access to the asset. I think the same thing causes people problems with stock options. Seems like an odd bit of legislation.
EDIT: IANAL, IANAA, etc...