WIS 73 heads northwest for about  to Plainfield where WIS 73 crosses I-39 (exit 136) and US 51 west of town. It continues heading west, crossing into Adams County at County Highway D. WIS 73 straddles the Adams-Portage county line for about four miles. It then enters Wood County before WIS 73 continues west-northwest to WIS 13, where it has a brief overlap with WIS 13.
WIS 73's route begins in Wisconsin and heads northwest towards Plainfield, crossing I-39 (exit 136) and US 51 west of town. It continues westward, entering Adams County at County Highway D before traversing the Adams-Portage county line for four miles.  Finally, WIS 73 enters Wood County before continuing westward-northwest to WIS 13, where it briefly intersects with WIS 13.