Anthropogenic litter (AL; trash) consists of different materials (e.g., glass, metal, and plastic), and is pervasive to all types of ecosystems, persistent in the environment, and increasing in abundance. Watershed land use metrics such as urban and impervious surface cover likely predict AL abundance but has not been well studied. We quantified relationships between watershed land cover and AL abundance and assemblage at 3 watersheds in North America which spanned a gradient of urbanization. At each watershed, we quantified AL at 4 sites: 2 tributaries, one mid-watershed, and one downstream. We collected AL in 4 stream habitats (i.e., benthic, riparian, floating, and overhanging vegetation), recorded material type, and expressed abundance as both count and mass of particles per area. Impervious surface and urban cover strongly explained variation in AL by count across sites. This is likely due to increased trash generation in urban areas and its rapid conveyance to streams by impervious surfaces. In contrast, there were few land cover predictors of AL by mass, which we attributed to high variation in material density among AL categories. The composition of AL was different among habitats, due to preferential retention of heavy materials in the benthic and riparian habitats and lightweight materials in the floating and overhanging habitats. These data will improve watershed-scale predictions of AL abundance and distribution and contribute to litter mitigation strategies for rivers and downstream ecosystems.