Theodore Roosevelt National Park in western North Dakota includes a rare, relatively large and undisturbed forest of plains cottonwood (Populus deltoides) along the Little Missouri River (LMR). Differences in the health of this forest between the North and South Units of the park, which are separated by 128 km along the river, led to an ongoing study of the potential effects of future climate change on streamflow through the park. USGS scientists used a combination of high-resolution imagery collected in 2010 by the U.S. Department of Agriculture’s National Agricultural Imagery Program (NAIP; https://gdg.sc.egov/usda.gov/) and a 30-m DEM from the National Elevation Dataset (NED; http://ned.usgs.gov/) to map geomorphic features within the North and South Units. The results enable an assessment of geomorphic differences between the two units and the possible effects of those differences on past and future forest regeneration. Scientists also are using the NAIP imagery in conjunction with the 2006 National Land Cover Database (NLCD, amended in 2011; http://www.mrlc.gov) to assess changes in land use that may be affecting streamflow in the LMR. Imagery and the 2006 NLCD data show that a large fraction of one subbasin is dedicated to crop cultivation. In this semiarid region, crop cultivation requires irrigation, and water withdrawals increase during dry years, reducing the flow that continues downstream. The remotely sensed data help explain observed differences in runoff response to precipitation among the LMR subbasins.