This is a rare sight!
This doe in Montana had triplets, and one of them is an albino. Having triplets is already uncommon in deer, so having one that is albino is rarely recorded. Most deer have twin fawns, and only about 15% have triplets. The odds of having an albino deer are about 1 in 30000 making this an exceptionally rare occurrence.
Here’s what the Montana Fish, Wildlife & Parks had to say
This amazing photo of a rare albino fawn was shared recently by Tracy Baker of Miles City. Only two fawns are visible in the picture, but in the span of a few minutes, the doe had a third fawn, making for a rare batch of triplets. Nature is pretty wild! Please remember to give does and fawns space this time of year, as does often stash a fawn while they feed and rarely abandon their young. The animals’ best chance of surviving and thriving is in nature, with humans at a safe distance!
If you see a fawn in the wild you should leave it alone. If you disturb the animal there is a significant chance that it will not survive.