Last year I bought Duluth Trading’s “Dry on the Fly” fleece lined nylon twill cargo pants and have used them for most of my winter treks. They are still sold by Duluth Trading (search for “Mens lined Dry on the Fly pants”)
This year Duluth Trading has a new winter pant for only $10. more than my DOTF pants. They are called Alaskan Snow pants.
Also this year DT has “Kenai Snow Bibs” and “Snowcat Pants”. The bibs have heavier “Sherpa” pile lining and knee-high leg zips. The pants have lighter microfleece lining. Both are made of nylon twillwith ripstop nylon double knees that accept knee pads.
All DT’s pants have a generous crotch gusset which makes them easy to climb with.