The ornamental design for an all terrainboard, as shown and described.
FIG. 1 is a perspective view of an all terrain board showing my new design.
FIG. 2 is a top plan view of the all terrain board of FIG. 1.
FIG. 3 is a bottom plan view of the all terrain board of FIG. 1.
FIG. 4 is a side elevational view of the all terrain board of FIG. 1. The other side elevational view is substantially the same; and,
FIG. 5 is an end elevational view of the all terrain board of FIG. 1. The other end elevational view is substantially the same.
The dashed lines appearing in FIGS. 1, 2, 4 and 5 illustrate unclaimed features shown for environmental purposes, which do not form a part of the claimed design.