Lidar data was collected on 24 and 25 May 2017 at the USGS debris-flow flume to monitor two gate-release debris flow experiments. A static prism of sediment was emplaced behind a gate at the top of the flume. Water was added via sprinklers to the surface and also via pipes to the subsurface, in order to saturate the sediment mass. The sediment mass moved down the flume as a debris flow when the gate was opened. Lidar data was collected from a Riegl VZ-400 terrestrial laser scanner to capture the mass failure. The lidar unit was modified to scan a narrow swath (approximately 1 mm) along the full profile of the constructed sediment mass. The lidar scan rate was set to re-scan every 0.017 s or at a rate of 60 Hz. The data contained herein ecapsulates entire lidar point cloud from the time before prior to movement through full failure of the sediment mass. The points are organized in rows. The columns are: ['xM', 'yM', 'zM', 'rangeM', 'thetaDEG', 'phiDEG', 'riegl_ref', 'timestampSEC', 'Line'] . The 'xM', 'yM', 'zM' values are the x, y, and z real world UTM coordinates with units of meters. The 'rangeM' is the distance of each point from the scanner with units of meters. The vertical angle of the lidar scanner is shown as 'thetaDEG' with units of degrees. Similarly, the horizontal angle of the lidar scanner is shown as 'phiDEG' with units of degrees. The 'riegl_ref' represents reflectance value computed from the intensity. The timestamp is the number of seconds since the beginning of the scan. The 'Line' column represents all the points that belong to a single lidar profile swath.