While pulks really excel on flat even terrain like frozen lakes, they can be used in not ideal situations. Sometimes almost necessary albeit not ideal. I have used them along the continuum from the ideal frozen lakes in the Adirondacks for enjoyable lakeside camping to almost bushwhack conditions bringing in 100+ pounds of roofing materials and tools for lean-to repairs.

We use half-inch fiberglass poles attached to the sleds and then waist belt. You want minimal give, and cross the poles to help with tracking. Never had one flip, even on serious side hills. the crossed poles help with this too. The biggest issue with the pulks is not uneven terrain or hills (though obviously uphill is harder). The biggest pain in the keister is blowdown and/or other obstructions when you must unhook and then lift or carry the pulk over something and then reconnect. Once or twice is no big deal, but it can be tiresome when the trail isn't cooperating. Deep snow can also be real tiresome. Once it took me 3 hours to go 7 tenths of a mile breaking trail through 3 feet of snow and dealing with bent over spruce trees obstructing the trail every 15 feet. On the return trip it took half an hour.
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