No salt on these dirt roads .5 ft of snow all winter and not maintained ,along a ridge at 6000 ft . Lots of salt in the alkali sags in the valleys and prairies way below and far from these snowshoes .

What Boco said same here always know that rabbits (snowshoe hares) are attracted camp fire ashes. People sometimes used to set foot traps in camp fire ashes back in the day.

Seen them eating sand or gravel before

The rabbits must like the potassium hydroxide (potash) in the wood ash.
It probably helps them digest the coarse food they eat in winter.

Lots of mammals eat wood ash. I think it may help settle their stomach's or provide needed minerals. I have had rabbits chew bbq briquette charcoal (burned and unburned) and when I lived in the country I would often see large numbers of butterflies congregated in a cold fire pit... particularly just after a rain.