The feeling of skiing in fresh snow, making new tracks is a very unique one, especially when the turns have been earned through sweat and effort, climbing uphill, step-by-step. Backcountry is a diverse category meaning the skis have to be too. What binds them together is the focus on weight reduction and the fact that they’re pushing the boundaries of ski design.
Where they differ is the emphasis placed on the up or the down.
Bigger models blur the lines to freeride and are created to hunt fresh snow or charge hard-to-reach areas; the slimmest skis are about the ascent and achievement as much as the ride back down.
A classic backocuntry ski has anything from 85mm up to 112mm in the waist. The sweet spot for an all-rounder is 90-95mm, not so big to be excessively weighty, wide enough to float and feel stable but slim enough to remain nimble. The radius will be medium to long for better stability in rough snow.
You'll find rocker will exist on the tip to aid float and handling. Narrower skis will have a flatter tail to improve grip, wider models will introduce a low rocker on the tail to improve release and handling in deeper snow.
The ideal size for a backcountry ski comes down to priorities. A balance of shorter for weight reduction when climbing up and longer for stability, grip and float when skiing down.