The following data is extracted from Genealogy and Biography of Ontario County, New York.
Peter Garlock, the first member of this family of whom we have definite information, was a descendant of Johann Christopher Gerlach, one of the immigrants from the Palatinate on the Rhine, in Germany. He was born not later than 1690. He was appointed the head man of the "dorfs" or villages in which a number of these immigrants were settled in 1710 and 1711. There were seven of these dorfs, on both sides of the Hudson river, in and opposite what is now (1910) Columbia county. Elizabethtown, over which Johann Christopher Gerlach was head man, was west of the river. In 1713 a body of these Palatines removed to Schoharie. They were in a miserable condition, having been unfairly treated in their former settlement, but happily were kindly received and charitably assisted by the Indians. The richness of the soil soon enabled them to improve their condition. Others followed within a few years, and one of the villages formed by them was named Gerlach's or Garlock's dorf, after Elias Garlock. About 1722 Elias Garlock removed to the Mohawk valley. Several of the Garlocks have won distinction in the revolution and in medicine. Peter Garlock had at least one child, Abram, referred to below.
Source: Genealogy and Biography of Ontario County, New York