US 10 enters Portage County as a freeway, and meets WIS 34 and WIS 13 south west of Junction City. WIS 34 splits to the north east of Junction City while US 10 turns east and bypasses Stevens Point. The highway then meets I-39/US 51 north of the city and runs concurrently with I-39/US 51 for about before exiting to the east of Stevens Point. At this point, US 10 becomes a multilane surface road for about six miles, then becomes an expressway and heads southeast, passing through Amherst and crossing into Waupaca County. US 10 bypasses the city of Waupaca to the south and junctions with WIS 22, WIS 54 and meets WIS 49 south. US 10 and WIS 49 turn eastward to Weyauwega then head south to Fremont where WIS 49 turns south and US 10 becomes a freeway at the junction with WIS 110. US 10 collects US 45 south in northwest Winnebago County for a southeast trek before US 45 splits to the south and US 10 turns east to rendezvous with WIS 441 at the junction with I-41/US 41 in Neenah. US 10 turns south off the WIS 441 freeway south of Appleton and turns east into Calumet County.