A prefabricated modular portable livestock shelter shipped unassembled includes a pair of end walls 22 and 24 attached to a side wall 26. In addition a roof 28 is attached to the end walls 22 and 24, and the side wall 26. The end walls 22 and 24 are connected by a front tubular side rail 30, a back tubular side rail 32, and a pair of tubular skids 34 by means of a tubular connector 36 and tubular connector fastener 38. Upturned ends 40 allow the shelter to slide easily over the surface of the ground. The shelter is secured by placing metal earth anchors 42 into the ground and fastening them to the shelter with a steel cable and clamp 44. The shelter can be configured in the winter to provide protection from wind while allowing exposure to sun. The summer configuration provides additional shade while allowing breeze to pass through the structure. A tractor or other suitable farm vehicle may fasten a chain to the metallic hooks 46 in order to drag the portable livestock shelter 20 over the ground to facilitate pasture, manure, and disease management. The structure can be disassembled to move from one location to another.