Metro North trains run every other hour at Wassaic and Tenmile River stations. There are no restrooms at the Tenmile River station. Check time table for schedule. Time your return to meet your train or end up with a long wait.
Author's cue sheet has lunch and attractions options. You can pre-order lunch to pick up and carry to eat at the Raptor Center.
Shorter, less hilly route option on that cue sheet.