US Post Office is located at 205 E Amelia St, Cassville, WI. This business specializes in Post Offices. US Post Office is open Mon, 9:05am-4pm; Tue, 9:05am-4pm; Wed, 9:05am-4pm; Thu, 9:05am-4pm; Fri, 9:05am-4pm; Sat, 9:05am-11am; Sun, Closed and accepts American Express, Discover, Mastercard and Visa.