Built by the Missouri Valley Bridge & Iron Co, of Leavenworth Kansas as Oklahoma Federal Aid Project No. 16 in 1919, the Calvin Bridge has carried many travelers across the Canadian River. In 1925, OK 12 was designated to cross the Canadian River via the Calvin Bridge. In 1926, this bridge served US 73 and US75. By 1936, only US 75 was routed across the Calvin Bridge.
Below, a view looking south thru the bridge. Each of the four pin-connected Parker spans is 190 feet in length.
Below, unfortunately, the ornate Missouri Valley Bridge Co. plaques have been replaced by these plaques put up by an unidentified agency. It is reassuring to know that the bridge's status as a historic structure is being noted, even if it is this minimal. Further work should be done to aid in preserving this historic bridge.
Below, an angled side view of the bridge looking to the southeast. A large pile of gravel made this view possible.
Above, a closer grade level view of the bridge looking in the same general direction. This bridge was one of the earliest state-standardized designs built in Oklahoma, and other bridges exist similar in design. The state-standardized designs represented a trend towards heavier bridges than the ones commonly built from the catalogs of bridge companies.
Below, a view thru the bridge. The bridge is of combination riveted-pinned construction. The composition of the deck on this structure is very interesting. The original wearing surface was wooden blocks laid out like bricks over the concrete deck. Later, these wooden blocks were paved over with asphalt.
Like many bridges in Oklahoma, this one has suffered from abuse and bad drivers. Though more substantial than the laced guards of the period, the channel guards on this bridge have been struck many times. The sway bracing and portals have also had damaged inflicted on them. The south portal was noticeably damaged, and a knee-brace was also missing. Although long bypassed by a more modern bridge, the Calvin Bridge stands as an excellent example of Oklahoma bridge building after WW1. The Calvin bridge has also outlived two replacement bridges since it was bypassed in the 1960's.