US Post Office is located at 132 2Nd St, Nashwauk, MN. This business specializes in Post Offices. US Post Office is open Mon, 9am-4pm ; Tue, 9am-4pm ; Wed, 9am-4pm ; Thu, 9am-4pm ; Fri, 9am-4pm ; Sat, 9am-10:05am ; Sun, Closed. and accepts American Express, Discover and Visa.