Plains pocket gophers are often underrated in terms of their impact on prairies. Prairie dogs get all kinds of attention because they stand at the edge of their burrows and make cute little sounds (they also get negative attention because they compete with cattle for forage). I would argue that pocket gophers have a similar degree of impact on their surroundings, and they’re in many more prairies than prairie dogs,but they get much less attention because they’re less visible.
The mounds from a pocket gopher's feeding tunnel are exposed after a spring prescribed fire. It'd difficult to tell whether the tunnel was made the previous fall or during the winter. The Nature Conservancy's Platte River Prairies - Nebraska.
The majority of pocket gopher tunnels are within a foot of the surface. Gophers feed on the roots of plants as they tunnel – mainly tap roots of wildflowers. Besides the impacts they have on plants from their feeding behavior, their mounds also have an impact on prairie plant communities. There is contradictory evidence about whether or not the mound creation provides space for new plants (thus increasing plant diversity) or removes plants and allows strong perennials to expand into the disturbed soil of the mounds (thus decreasing plant diversity), but most studies – especially in mixed-grass prairies have found an increase in diversity.
Many thanks to The Nature Conservancy’s Jim Luchsinger for help interpreting the photo and providing background information on pocket gophers.
The Prairie Ecologist 
Here’s an interesting tidbit: I think I remember pocket gopher-studying grad student at K-State speculating about the ability to “sex” the pattern of mounds in a pasture. If the mounds are in a scattered arrangement, it might indicate a female wandering in her search for food (roots). If the mounds were in a more or less straight line, it might indicate a male in search of a female (i.e., in search of a female tunnel system). Or was it the other way around?
Makes me wonder, if the straightness of a mound sequence (such as depicted in your photo) is deliberate, how do they navigate without visual cues to maintain their course? Sensitivity to the Earth’s magnetic fields?