Dispersing young beavers can and will do a half mile easily. At least here they do. I live in mountains, and new colonies often are at the end of an elevation change that 99% of the human population will decline on a day hike: down one fork and up another, or over the point in some cases. There are no other routes. Our beaver works lie in the relatively level heads of high valleys. Major tributaries usually join below that elevation, so to get to another suitable drainage they must go down and then up again, or they must go over the point between. Somewhere in my mental archive is a note about a beaver cutting in an odd upland location, but right now I don't have any more on the incident than this.
What might be unusual in your case is the time of year. But the book on beavers has not been completed. Or at least I haven't read the latest edition.
I've heard of snapping turtles in the uplands going from one creek to another or dropping eggs well away from one. You'd never guess that they'd get so high up such little streams and then haul out. So far from the kind of place where you'd usually put them.