Kenneth,
The documentation placed online entitled “Heirs of John Montgomery Rejected Claims Bounty Land” is great support for Nathan as a child of Alexander and Barbara Harris. My favorite Montgomery book listed below did not have Nathan as their child.
I suggest you get in touch with the Magoffin County Historical Society, Box 222, Salyersville, Kentucky 41465 and order the 3 volumes of “The Montgomery Family” because John Montgomery who died in Peoria County, and Alexander, his brother, have many descendants in this area. They also have a website.
Many pioneers passed through Salyersville from Virginia and the historical society is intent on remembering them.
Congratulations on matching your ydna with your family tree!
Kay