It was early in the morning, the shadows still long on the north slopes of the mountains and ridges. We'd just left the first hunter truck of the morning (Empty, of course. This is prime hunting time, and any hunter worth their salt is going to be out and about on foot.), and were slowly driving up the ridge to the next valley.

When I suddenly realized we were being passed.

By a deer.

A mule deer fawn, to be exact. Bounding past us, across the knee-deep sage, towards a doe and another fawn feeding up the draw.

Well, that's no surprise. Startle a fawn almost anywhere, and it's going to go running to mama. Even faster than a truck on a rutted dirt road.

But the fawn didn't run to the doe. Instead, it blasted right past her and her fawn, circled them one and a half times, then went bounding back down the draw, its speed unchanged.

Up the ridge on his right, around a couple small pines, and back he came, barreling down at the doe and fawn. Only to circle them once again, the second fawn watching wistfully as this youngster circled them both, then bounded back down the draw.

At the bottom of the valley, the hyper fawn disturbed another doe and fawn I hadn't noticed before, circling them and dashing through the cottonwood stand in the process. This third fawn joined in the game, and they gave chase to each other through the trees.

For only a moment. Then the third fawn returned to the serious business of eating, and laying on body mass for the coming winter.

While its sibling or cousin continued to bound through the trees.

Scientists have a word for this behavior.

It's called "playing".

And the fawn was still at it when we crept out of sight over the ridge.