Please note that this route follows an unpaved trail. Roots, stones, mud, gravel and a few steep sections. That said, it is a most worthy route for a number of reasons. For the gravel rider interested in advancing skills, it is a step up from hard pack, yet not a giant one. Alternative lines to obstacles are always present. Many curbs have been made bike friendly over the past year. Those that present as a challenge can be walked to avoid pinch flats and unsure landings. When comparing the OCA and the Trailways, both are designated motor vehicle free, you will trade the inconvenience of more road crossings for the challenges of trail/rough road and a more bucolic environment, history as reflected in its infrastucture, and occasional unexpected vistas. Your average speed will be less than the Trailways, understanding riding the OCA is less about getting from point A to B than the going itself. Most sections are not beyond the capabilities of a competent road rider on 25's. This is a route that should be part of the CV of a well-rounded NYCC rider.
Note: there is one very steep downhill section just before Ogden Rd, case it out before committing to descend it.
Follow the Old Croton Aqueduct Trail (OCA) back to its source. Take Metro North railroad back to the city. Or find your way back via the County Trailways, 6 miles: https://ridewithgps.com/routes/35710619
The OCA is a rough trail, unpaved except in places. If you don't like what you have found you can always look for the nearest Metro North Hudson Line station to return. And that is one of the beauties of this route. You can do it off-season or in questionable weather, knowing you have nearby rail access for a bailout along the route.
Ken has added viewpoints and resources along the route. Check the RWGPS map for these icons. Here are Ken's original notes:
A few more links:
The OCA Trail Map:
https://parks.ny.gov/parks/attachments/OldCrotonAqueductOldCrotonAqueductTrailMap.pdf
OCA State Park:
https://parks.ny.gov/parks/96/details.aspx
Croton Aqueduct Wiki:
https://en.wikipedia.org/wiki/Croton_Aqueduct
(editor's note again: thanks to Brian Sullivan for helping to update this route as of April, 2021)
HS 4/15/2021