Hoofbeats on the Turnpike by Mildred A. Wirt (Penny Parker #11)

HOOFBEATS ON THE TURNPIKE is #11 in the Penny Parker Series by Mildred Wirt Benson.

Penny is in need of money, as usual, and is highly interested when a man shows her a clipping offering a reward for any information leading to the capture of the Headless Horseman. Penny and Louise travel to Red Valley to search for the horseman and find themselves trapped in a flood after a dam breaks.