Here's a video produced by Kentucky Life of KET and published on Dec 15, 2014.

Featured is Historical Marker 72: Dr. Thomas Walker in Knox County, Kentucky.

Twenty years before Daniel Boone arrived in Kentucky, a Virginia "gentleman physician" surveyed and explored the southeastern region of the state.

In 1750 Dr. Thomas Walker of Virginia led the first known English expedition through the Cumberland Gap. Walker, exploring for the Loyal Land Company, named the mountains and the gap after the Duke of Cumberland, the son of King George II. Today, at the Dr. Thomas Walker State Historic Site southeast of Barbourville, visitors can see a replica of the cabin Walker constructed in 1750 to lay claim to the lands he had surveyed.

A number of historical markers detail the routes, the survey notes, and the impact of Walker's travels through the area. Marker 2,045 in Bell County marks the site where Walker first viewed the Cumberland River. Marker 903 in Paintsville marks where Walker named the river Louisa, honoring the daughter of King George II. Walker's explorations in Kentucky were brief; he passed through the Gap on April 13, 1750, and returned to Virginia three months later, on July 13.