On the other hand, those tires which feature a big slab of rubber with a modest thread cut in, such as the Schwalbe Marathons will wear forever but ride like a dead fish. I have a 26 x1.75 Marathon and find it amazingly heavy and slow.
Here's a good thread from bikepacker.net on what tires people use for the Great Divide. The WTB nanaraptor and the Geax Saguaro seem popular.
Here's some test data. The Geax looks good, and the Continental X king looks phenominal.