I've flown on Southwest a number of times (more on why I usually fly Southwest
on my snowboard trips) with a snowboard and have never been charged an overweight/oversize fee for portage of my board bag, which usually also contains my boots, pants, jacket, etc. My board is 163cm and the bag is 165 (65") so it definitely exceeds the stated limit.
Southwest also charges $0 for second
I've found they consistently have the lowest fares, especially when the baggage fees are taken in to consideration, and since they fly to Reno/Tahoe, Denver, Salt Lake City, L.A., Seattle/Tacoma and Portland, they can get you to pretty much any of the big resorts.
They don't charge ridiculous rates for one-way flights, either. NWA/Delta charges the same price for a one-way flight as they do for a round-trip. THis means you could fly in to SLC/Park City for a few days, hop on the Greyhound bus line to Denver and hit up Breck for a few more days, and fly home from Denver, at a very reasonable price.
Additionally, they have $0 fee for changing your flight, so if you decide to shorten/lengthen your trip, or to change the dates altogether, all you have to pay is the difference in fare (they will credit you if the new fare is lower - which can also be used to re-book the same
dates at a lower fare if one becomes available!). I think NWA/Delta charges $150 for a change.