This happened to me last year. It happened to be the first steelhead I ever hooked. It spooled me after I ran as far as I could and ended up inwater nearly to the top of my waders. Unfortunately, it hasn't happened again.

The advice I got from this board was to try free spooling it. The idea is to fool the fish into thinking it's loose and doesn't have to keep bolting which gives you just enough leverage to get it turned.

A guide I was out with also suggested diving the tip of your rod in the water when all else fails. Supposed to get more resistance from the line that's now under water.

Bruce