The single loop run course travels north through the Croton River Valley until reaching Croton Dam Park. There you'll climb up to the Old Croton Aqueduct which will take you to the top of the Croton Dam. You'll run on the new out/back section of Croton Dam Road which is shaded and partly packed dirt. On the return, run across the dam spillway and shed minutes off your time running down Rt 129 back to the sactuary streets of Croton.
The run course has a net elevation gain on the way out, which means a nice elevation loss for the return. So practice that leg turnover.