Riparian vegetation and topography control the timing and magnitude of stream surface radiation, and thus must be accounted for in stream temperature models. Historically, these influences have been quantified by geometric models based on field-measured tree heights, stream-based measurements of horizon angles, and analysis of hemispherical photography. LiDAR elevation data are becoming more readily available, and some efforts have been made to use them to model stream shading. The objective of this research was to develop a model that combines LiDAR data with a coarser-resolution topographic DEM to model the contributions of riparian vegetation and surrounding topography to shading and view factors. At each time step, the model computes separate horizon angles for vegetation and topography for the solar azimuth angle, which are compared to the solar elevation angle. The model also computes sky view factors for each grid cell. Application of the model to a north-south-oriented 24-km-long stream reach in a glaciated mountain valley demonstrated the dominant shading effect of the riparian zone throughout the entire stream reach, although topographic shading from the steep eastern valley wall contributed to early morning shade. Given the increasing public accessibility of both LiDAR and topographic DEMs, the model developed in this study has the potential for broad application.