Bridge No. 12 is a Warren pony truss bridge in Hay Creek Township, Minnesota. The bridge is 63 feet (19 m) long and 16 feet (4.9 m) wide and carries Township Road 43 over Bullard Creek. It is built of angle sections riveted together, as recommended in the engineering textbook The Design of Highway Bridges published in 1908. During this time, the state government was attempting to standardize design and construction of bridges by financial incentives, rather than proposing legislation. The bridge is listed on the Iron and Steel Bridges in Minnesota Multiple Property Submission.