US Post Office is located at 48 Mill St, Elsah, IL. This business specializes in Post Offices. US Post Office is open Mon, 8am-4:59pm; Tue, 8am-4:59pm; Wed, 8am-4:59pm; Thu, 8am-4:59pm; Fri, 8am-4:59pm; Sat, 8am-9:59am; Sun, Closed and accepts American Express, Discover, Mastercard and Visa.