Abstract: A three-sided, rectilinear bridge or culvert structure comprises a pair of vertical sidewalls set in preformed or cast in place footers or existing supports and an integral, planar, horizontal span. The footers preferably include a sidewall receiving channel on their upper surfaces. There is no lower or bottom portion of the structure such as is found in conventional box culverts and thus, that region between the footers and sidewalls is open and readily permits water flow through the structure in its natural watercourse, lessening the likelihood of debris collection within the structure. The structure is cast concrete reinforced with conventional reinforcing bar or welded wire mesh. A wide range of rise/span (height/width) proportions may be accommodated in structures having spans up to about thirty feet.