What are these dirt snake things, anyway?

Now that the snow has mostly melted, we get to look at what it has left behind. Fortunately for me, my house is off the main road and I don't have a dog, so some of the things that can make mud season so icky aren't part of my landscape.

Instead, I've got things like this:



These are ridges of loose dirt, about 5 cm wide and a few cm tall. They are just downhill from my driveway, on a 15 degree slope, but there are also some on the flatter slope of the nearby drainage. They lie across last year's grass, and across some cobbles near the side of the driveway. I've seen similar features above treeline, soon after the snow has melted, and had lots of discussions about what they are. (Critter burrows? Remnants of running water, like teeny eskers?)

Anybody know of literature on things like these? What are they?