There are paths or runways of clipped turfgrass throughout my yard.  What is causing this and how do I repair my lawn?

Prairie and Meadow Voles scar lawns by constructing surface runways (one to two inches wide) and clipping grass very close to the roots. Runways are most visible after snow melts. Small holes lead to underground runways or nesting areas.

Voles are small, mouse-like rodents that exist throughout Nebraska. Their short tails (about 1 inch long), stocky build and small eyes distinguish them from true mice.

Vole damage to lawns usually repairs itself during spring growth and is not permanent.

Vole damage is costliest when they eat the inner green bark layer of trees and shrubs during winter. This gnawing can severely damage or kill young trees and shrubs. In gardens, voles can clip off young plants and dig up seeds. They also eat leaves, shoots, roots, tubers and seeds of most grasses, forbs and broadleaf flowering plants.

For more information review, 

Controlling Vole Damage