FIG. 1 is a perspective view of a snow guard in accordance with the present design; FIG. 2 is a front elevation view thereof; FIG. 3 is a back elevation view thereof; FIG. 4 is a first-side elevation view thereof; FIG. 5 is a second-side elevation view thereof; FIG. 6 is a top view thereof; and, FIG. 7 is a bottom view thereof.