Habitat complexity in rivers is linked to physical processes that act at various spatial scales and requires dynamic hydrologic and geomorphic conditions. On regulated rivers in the western United States, tributaries may provide important resource inputs and serve as sources of dynamism on regulated systems, offering blueprints to guide restoration of habitat complexity in riparian areas. We investigated spatial patterns and extent of tributary influence on riparian habitat complexity along regulated reaches of the Colorado and Dolores Rivers in the western United States. We hypothesized that riparian habitat complexity, measured as geomorphic and vegetation response, would peak at or downstream of tributary junctions and that the influence of tributaries and patterns in riparian and geomorphic response would vary across grain size. Using a combination of remote sensing and spatial analysis, we classified fluvial features and riparian cover classes to examine patterns along these regulated rivers with measures taken at 10, 25, and 100 m intervals. Our results showed that complexity patterns increased closer to tributary junctions and patterns differed across scales. Tributary junctions offer dynamism, delivering critical resource inputs such as water and sediment that may serve as refugia and provide the habitat complexity critical for riparian restoration outcomes.