Livingston County was formed Feb. 23, 1821, from Genesee and Ontario Counties. A portion of Allegany County was annexed in 1846 followed by a second portion in 1856. Livingston's parent county, Ontario County, was formed from Montgomery County in 1789. Montgomery was formed from Albany County (one of the original NYS counties) in 1772 and was known as Tryon County until 1784. Livingston is surrounded by Monroe, Ontario, Steuben, Allegany, Wyoming, and Genesee counties. The 1860 census showed 39,256 residents. The Genesee River cuts through the northwestern portion of the county. Conesus Lake (near the center) and Hemlock Lake (along the eastern border) are the only considerable bodies of water.
http ://www.rootsweb.ancestry.com/~nyliving/ (broken link)