Plots of the difference between photogrammetric models and the lidar-only DEM showed that larger false image matches (blunders) were reduced in later models (Fig. 5), a result of model adjustments being better constrained by a greater number of GCPs.Despite the promising results of our check-data analysis plots of elevation change between photo models and the 2003 lidar model (Fig. 5) and between photo models and the 2005 lidarmodel (Fig. 6) showed thatDEMerrors of up to 2m remained in the small snow-covered areas adjacent to the glacier backwall and higher-elevation tributaries.