Cross-section geometry data at selected bridge sites in Montana

The U.S. Geological Survey (USGS), in cooperation with the Montana Department of Transportation (MDT), collected channel cross-section geometry data on the upstream and downstream sides of selected highway bridges in Montana. The cross-section data typically extend the full width of the streambed at the bridge opening and up the abutments so that local pier scour effects and more general geomorphic scour processes can be distinguished. Contraction scour was not considered a factor mainly because none of the bridges reflect a substantial contraction of flow, given the spring runoff conditions experienced. The purpose of the data collection is to determine if scour and channel instability occur in the vicinity of the bridge structures. Data were processed, analyzed, and compiled for bridge scour monitoring, facilitating better understanding, documentation, and prediction of scour processes.