Determination of the structural behavior of historical monuments under different loading types is a crucial task for the preservation and conservation of these structures for transferring to future generations. In this study, the behavior of 800 years old historical Erzurum Çobandede bridge under flood load is investigated. To determine the flood load subjected to the bridge, the best probability distribution model was selected for the observed data obtained from flow gauging stations in the nearby Kağızman Basin and then flood data at different return periods were estimated with this model. The behavior of the bridge under maximum flood load is determined. It is specified that the bridge will not suffer serious damage under the possible maximum flood load in different return periods.