We compared the structure of riparian willow (Salix spp.) habitat and songbird diversity across two regions of the Greater Yellowstone Ecosystem: Gallatin National Forest and Yellowstone National Park in the north and Grand Teton National Park in the south. The average height of willows was greater (151 vs. 65.9 cm) in the Teton region, and the average density of willows was greater (45.2 vs. 26.1%) in the Gallatin. The average height of willows was the most important variable explaining songbird species richness and abundance across these two regions. Songbird richness and abundance was greater (6.1 vs. 3.1 species; 11.7 vs. 5.6 individuals) in the Teton region. Larger patch size in the Tetons could be a factor contributing to the higher level of diversity but was not statistically significant. Individual species responses to habitat structure varied based on the nesting height preference of the species. Species that nest above the ground or in taller vegetation had abundance positively correlated with average willow height (Yellow Warbler [Dendroica petechia] P < 0.001; Fox Sparrow [Passerella iliaca] P = 0.001). Yellow Warbler, Willow Flycatcher (Empidonax trailii), Fox Sparrow, and Common Yellowthroat (Geothylpis trichas) all had higher abundances in the Teton sites. The difference in willow habitat structure across these regions is likely influenced by historic differences in elk (Cervus elaphus) browsing in the northern regions of the Greater Yellowstone Ecosystem.