Try this link for a weight calculation formula. Since the body mass densities differ in salmon and steelhead you have to use two separte formulas. Now don't go quoting me on this since I am just going off of what I've been told by RT. Then again RT seems to think that a lot of things are bigger than they really are :p
http://www.geocities.com/Yosemite/Trails/8482/calc.html

The formula on this page says that your fish was 44.5lbs. NICE!

[ 10-01-2001: Message edited by: Kid Sauk ]