The Mountain Fork Bridge is a historic bridge in rural Polk County, Arkansas. It carries County Road 38 across Mountain Fork Creek north of Hatfield and southwest of Mena. The bridge consists of two spans of steel Pratt pony trusses, with a total length of 406 feet (124 m), including approach spans. The trusses are set on piers consisting of steel rings filled with concrete; each of these spans is 80 feet (24 m) long.