Culverts? Concerns is an unmarked rapid on French Creek with limited documented information, making it potentially challenging for paddlers unfamiliar with the local river conditions. The section near Custer State Park's eastern boundary may contain unpredictable water features, rocks, and potential strainers that require careful navigation and scouting before attempting. Due to limited beta on this specific rapid, experienced paddlers should approach with caution and be prepared for variable water levels and terrain.