Ephemeral gully erosion from agricultural regions in the Pacific Northwest, USA Soil erosion continues to be problematic financially and environmentally with the USEPA ranking sediment as one of the top ten pollutants of concern in the USA. One aspect of erosion often overlooked is the role of ephemeral gullies in terms of quantity of sediment produced and amount exported to nearby waterways. Current physically-based and empirical models are inadequate for predicting this type of erosion particularly at the watershed scale. A new methodology for predicting the quantity and location of sediment delivery was developed and tested via a case study. Aerial ephemeral gully erosion rates varied from 33.6 mton/km2 (0.15 U.S. tons/acre) in the Big Bear Creek basin to 88.4 mton/km2 (0.39 U.S. tons/acre) in the Middle Potlatch Creek basin representing 2.3 to 7.7% of the total surface sediment load. This information was used to develop a predictive Erosion Potential Index (EPI) that uses LANDSAT aerial imagery combined with readily available soils information and a digital elevation model to identify the most probably locations of ephemeral gully development. High resolution aerial imagery was used to quantify actual ephemeral gully locations which were then compared to the EPI predicted locations to verify the procedure. High resolution aerial imagery was also used to quantify the amounts of soil erosion from ephemeral gullies in basins of the Potlatch River system.