Off-road tires for use in Nevada are quite a bit different than off-road tires for use in northern Saskatchewan. From what I've seen in the southwest, an aggressive tread is usually not all that necessary but a tough sidewall is. A tire for driving through 12 inches of snow is a lot different than a tire for crawling through the rocks. In the gumbo on the prairies, an aggressive tire with good self-cleaning qualities is what you need so you can spin the mud out. WH