The goal of this project is to acquire an open-access, marine wide-angle seismic reflection/refraction dataset across the Cascadia accretionary wedge encompassing the full length of the margin. This survey consisted of the deployment and recovery of short-period multicomponent ocean bottom seismometers. The sensors recorded the controlled-source acoustic signals of a seismic reflection survey off the Cascadia margin conducted in Summer 2021 (R/V M.G. Langseth cruise MGL2104). The data collected are open-access and will be released to the community immediately after acquisition and checked for quality control. The data will be reduced to standard digital formats as well as provided as a raw continuous digital time series.