This dataset contains topographic cross sections spanning the river channel along an approximately 15 kilometer (km) reach of the Kalamazoo River between the Trowbridge Dam and Allegan, Michigan (MI). The 147 cross sections are oriented perpendicular to the channel and spaced evenly every 100m along the reach to represent variability in channel geometry. The cross section data were extracted from a digital elevation model (DEM) comprising topographic and bathymetric data for Area 5 of the Kalamazoo River (Quantum Spatial, 2017). The DEM was created from topobathymetric aerial lidar data collected in November, 2016, combined with multibeam bathymetric data collected in May, 2017 to fill gaps in the lidar. Bankfull hydraulic geometry attributes and complexity metrics were calculated for 105 cross sections upstream of the beginning of the impoundment caused by Allegan City dam. Historical cross section data from 2011 at one location in the study reach were compared to a DEM-derived cross section to evaluate channel stability at that location. cross section data are provided in tabular and graphical form in Excel files (Reference Reach Spreadsheet; Mecklenburg, 2006). Data are split in three spreadsheet files by major river section boundaries defined by valley confinement (upper confined, unconfined, lower confined). The data are also provided as individual CSV files for each cross section (in a zipped archive), which contain X and Y coordinates in addition to elevations and cross sectional distance values. cross sections are named by their distance, in meters, downstream from the start of the reference reach. The spatial location of the cross sections is provided by an associated polyline shapefile included in this data release.