Grain-size data, including grain size, cumulative frequency, and median, was determined from samples collected at three bluff locations in the vicinity of Wainwright, Alaska. The different locations (termed W1, W2, and W3) represent three different slope-failure modes. Sediment grab samples for most bluff locations were collected in August 2009, while sediment samples from the bluff at site W3 and multiple foreshore locations were collected in September and October of 2009. Two of the grab samples were sieved and analyzed for grain size distributions (7 classes ranging from 0.06 to 0.72 mm). The grain size distribution of the remaining samples was determined from referenced photographs of collected samples taken in the lab following the method of Barnard and others (2007) using two-dimensional spectral decomposition of sediment images (Buscombe and others, 2010). Results of sieved samples were used to verify mean grain-size values obtained with the image processing algorithm. Data are available in a single csv file.