Lasiurus intermedius (Northern Yellow Bat) and Perimyotis subflavus (Tricolored Bat) are species of conservation concern in South Carolina and are threatened by loss of roosting habitat. To better understand summer roost selection, we radio-tracked individuals to roost trees during May through August of 2018 and 2019. We characterized roost trees, sites surrounding roost trees, and unused but available trees for each roost occasion. We used discrete-choice models to test hypotheses of factors influencing roost-site selection. Tri-colored Bats used foliage and Tillandsia usneoides (Spanish Moss) in hardwood trees and selected trees with high densities of Spanish Moss. Northern Yellow Bats used dead palm fronds in Sabal palmetto (Cabbage Palm Trees) or Spanish Moss in trees with high densities of Spanish Moss. Our results suggest that conservation of maritime and bottomland forests with trees that have high densities of important roost structures like Spanish Moss and dead palm fronds would benefit these species.