Elevation grids can be converted to GIS vector format as contour lines at an interval of your choosing. An appropriate contour interval depends on the grid resolution, topographic relief, and anticipated map or display scale at the data will be plotted. The PRISM-based 5m grids can reasonably support contour intervals as low as 3 meters. Contours can be output in common vector formats such as SHP, TAB, or KML.