Jim, I think the Post Rd mentioned is actually Old Post Road which still carries that name in northern towns. It is now Route 9. Route 9 starts somewhere in Westchester Co, or even lower and continues up to Albany. There were tolls on this road at one time. I'm not sure if the name Old Post Rd continued above Albany, but I'm pretty sure it's the same as post road. I'm not sure which farm they are mentioning. If they are beginning the mile from Fishkill Landing on the Hudson River it shouldn't be too far from the river. I would check with the Fishkill Historical Soc. Good Luck