Question: What Virginian explorer passed through an area near the Clinch River?

full_context: Document 1: Joseph Martin (general): Joseph Martin (1740–1808) was a brigadier general in the Virginia militia during the American Revolutionary War, in which Martin's frontier diplomacy with the Cherokee people is credited with not only averting Indian attacks on the Scotch-Irish American and English American settlers who helped win the battles of Kings Mountain and Cowpens, but with also helping to keep the Indians' position neutral and from siding with the British troops during those crucial battles. Historians agree that the settlers' success at these two battles signaled the turning of the tide of the Revolutionary War—in favor of the Americans.
Document 2: Thomas William Walker: Thomas William Walker, ONZM (2 July 1916 – 8 November 2010) was an Anglo-New Zealand soil scientist. He was known as "Tom" or "John" or "Johnnie" after the Johnnie Walker brand of whisky, or "The Prof" to students and latterly viewers of "Maggie's Garden Show". To his family he was "Baba".
Document 3: Fort Chiswell Site: Fort Chiswell Site is a historic archaeological site located at Fort Chiswell, Wythe County, Virginia. It is the site of a frontier fort built in 1758 as an outpost during the French and Indian War. The fort was situated at the junction of the Great Trading Path and the Richmond Road, near the New River. The fort fell into disrepair in the 18th century as both the county seat and courthouse were moved from Fort Chiswell to the county seat of Wytheville, 12 miles to the west. The remaining foundations of the Fort and its surrounding buildings were completely covered over during the construction of I-77 in Wythe County during the 1970s. There is a pyramid shaped historical marker of sandstone situated approximately 200 yards west-northwest of the fort's original location next to the old chicken house.
Document 4: Flanary Archeological Site: Flanary Archeological Site is a historic archaeological site located near Dungannon in Scott County, Virginia, United States. Located across the Clinch River from Dungannon, the site was inhabited as early as 6000 BC and remained in periodic use into the Woodland period, with occupation potentially continuing until c. AD 1600. The terminus ad quem for occupation is 1750, when Thomas Walker's expedition passed through the area and found no Indian villages. Excavations conducted in 1977 in preparation for the construction of a bridge revealed that the village site, featuring posthole patterns indicating a palisade surrounding the village, lay primarily south of the bridge in the vicinity of a 1764 log cabin.
Document 5: Horr's Island archaeological site: The Horr's Island archaeological site is a significant Archaic period archaeological site located on an island in Southwest Florida formerly known as "Horr's Island". Horr's Island (now called "Key Marco", not to be confused with the archaeological site Key Marco) is on the south side of Marco Island in Collier County, Florida. The site includes four mounds and a shell ring. It has one of the oldest known mound burials in the eastern United States, dating to about 3400 radiocarbon years Before Present (BP). One of the mounds has been dated to as early as 6700 BP. It was the largest known community in the southeastern United States to have been permanently occupied during the Archaic period (8000 BCE-1000 BCE).
Document 6: Cleek-McCabe Site: The Cleek-McCabe Site is a Middle Fort Ancient culture (1200 to 1400 CE) archaeological site near Walton in Boone County, Kentucky, in the northern Bluegrass region of the state. It is situated on Mud Lick Creek approximately 11 km from the Ohio River. The site has several components, including two mounds and a village.
Document 7: Piney Creek South Site: The Piney Creek South Site is a prehistoric rock art site located on the south side of Piney Creek in Piney Creek Ravine State Natural Area in Randolph County, Illinois. The site consists of two groups of petroglyphs drawn on a sandstone rockshelter. The petroglyphs most likely date from the Late Woodland period, which lasted from 450 to 900 A.D. The larger petroglyph group contains ten designs: four anthropomorphs, a quadruped resembling a deer, three crosses, and two pits. The four designs in the smaller group include two anthropomorphs, a group of pits extending from an anthropomorph's head, and a pecked area. Several of the anthropomorphs appear to have wings, two are carrying shields or rattles, one appears to have a beak, and one may have a crude penis. The site likely had spiritual significance, and the anthropomorphs may represent shamans, who were frequently depicted with wings in Native American art.
Document 8: Thomas Gaddis: Thomas Gaddis (1742–1834) was an officer in the American Revolutionary War. He was born December 28, 1742, in Winchester, Frederick County, Virginia and married Hannah Rice in 1764; the same year he built Fort Gaddis, a refuge from the Indians, located on the Catawba Trail. In fact, Pennsylvania and Virginia had conflicting claims in the area Gaddis settled. Though he maintained his loyalty to Virginia, Gaddis also protected his investment by recording his patent with Pennsylvania authorities. By 1773, both states created new geo-political boundaries in recognition of increased white settlement. Pennsylvania formed Westmoreland County out of the larger Bedford County, and Virginia established the District of West Augusta. In 1776, West Augusta was further divided into three counties: Ohio, Youghiogheny, and Monongahela, where Gaddis and his family resided.
Document 9: James Robertson (explorer): James Robertson (June 28, 1742 – September 1, 1814) was an American explorer, soldier and Indian agent, and one of the founding fathers of the State of Tennessee. An early companion of explorer Daniel Boone, Robertson helped establish the Watauga Association in the early 1770s, and helped defend Fort Watauga from an attack by the Cherokees in 1776. In 1779, he cofounded what is now Nashville, and was instrumental in the settlement of Middle Tennessee. He served as a brigadier general in the Southwest Territory militia in the early 1790s.
Document 10: Daniel Boone: Daniel Boone (November 2, 1734 [O.S. October 22] September 26, 1820) was an American pioneer, explorer, woodsman, and frontiersman, whose frontier exploits made him one of the first folk heroes of the United States. Boone is most famous for his exploration and settlement of what is now Kentucky, which was then part of Virginia but on the other side of the mountains from the settled areas. As a young adult, Boone supplemented his farm income by hunting and trapping game, and selling their pelts in the fur market. Through this occupational interest, Boone first learned the easy routes to the area. Despite some resistance from American Indian tribes such as the Shawnee, in 1775, Boone blazed his Wilderness Road through the Cumberland Gap in the Appalachian Mountains from North Carolina and Tennessee into Kentucky. There, he founded the village of Boonesborough, Kentucky, one of the first American settlements west of the Appalachians. Before the end of the 18th century, more than 200,000 Americans migrated to Kentucky/Virginia by following the route marked by Boone.
Document 11: Ely Mound: Ely Mound is a historic burial mound located near Rose Hill, Lee County, Virginia. It is considered the best-preserved Mississippian culture site in Virginia. The mound dates to the Late Woodland-Mississippian Period (AD 1200-1650), during which more complex societies and practices evolved, including chiefdoms and religious ceremonies. Often, temples, elite residences, and council buildings stood atop substructure or townhouse mounds such as Ely Mound.(Decaying cedar posts remained in the ground in the late 1800s, and were frequently struck by plows). Lucien Carr, assistant curator of the Peabody Museum of Archaeology and Ethnology in Boston, led an excavation here in 1877. At that time, the mound measured 300 feet in circumference, and 19 feet in height. Excavation lasted a little over two weeks, with skeletons, pottery, and arrowheads of white flint being unearthed. Unfortunately, one man was killed within a few feet of the bottom of the mound when the shaft he had been digging in collapsed. Several other men were injured. The mound has remained undisturbed ever since.
Document 12: Richard Callaway: Richard Callaway or Richard Calloway (June 14, 1717 – March 8, 1780) was a longhunter and early settler of Kentucky. Born in Caroline County, Virginia, Callaway joined Daniel Boone in 1775 in marking the Wilderness Road into central Kentucky, becoming one of the founders of Boonesborough, Kentucky. He took part in organizing the short-lived colony of Transylvania.
Document 13: Windover Archeological Site: The Windover Archeological Site is an Early Archaic (6000 to 5000 BC) archaeological site found in Brevard County near Titusville, Florida, USA, on the central east coast of the state. Windover is a muck pond where skeletal remains of 168 individuals were found buried in the peat at the bottom of the pond. The skeletons were well preserved because of the characteristics of peat. In addition, remarkably well-preserved brain tissue has been recovered from many skulls from the site. DNA from the brain tissue has been sequenced. The collection of human skeletal remains and artifacts recovered from Windover Pond represent among the largest finds of each type from the Archaic Period.
Document 14: Thomas Walker (explorer): Thomas Walker (January 25, 1715 – November 9, 1794) was a distinguished physician and explorer from Virginia; in the mid-18th century, he was part of an expedition to the region beyond the Allegheny Mountains and the unsettled area of British North America. Walker and fellow Virginian, Indian agent, explorer for Patrick Henry, legislator of three states, surveyor of KY/VA & TN/NC borders, and later Revolutionary war general, Joseph Martin, were some of the first colonialists to travel in this area. Martin's son, Revolutionary War officer Col. William Martin, describes the naming of the area and river in a letter to historian Lyman Draper,
Document 15: Joe Bell Site: The Joe Bell Site (9MG28) is an archaeological site located in Morgan County, Georgia underneath Lake Oconee, but prior to the 1970s, it was located south of the mouth of the Apalachee River on the western bank of the Oconee River. The junction of these two rivers could be seen from the site. This site was first visited by Marshall Williams in 1968 at the suggestion of the site’s landowner, Joe Bell, who had discovered various artifacts while the site was being regularly plowed. Because of Interstate construction, Marshall Williams and Mark Williams discovered this site during surface surveys and excavations of the plowed areas. The site was excavated and analyzed by Mark Williams as part of his PhD dissertation. During the 1969 excavations, four areas within the site were designated for excavation. In Areas 1-3 various five foot square units were excavated. No excavations were done in Area 4 in 1969. Large quantities of small potsherds were discovered during these excavations, and they ranged from the Duvall Phase in Area 1 to Bell Phase in Areas 2-4. As part of the 1969 excavations, a road grading machine took off the topsoil of twelve strips on the site. This uncovered Features 1 and 2, and they were completely excavated. In 1977, the site was revisited by Marshall Williams and Mark Williams. Since various plans threatened this site, major excavations took place from June 15, 1977 until September 16, 1977 by Mark Williams. Most of the work centered on Area 2 or the Bell Phase portion of the site. The Bell Phase portion of this site was probably no more the 1.5 acres . Because of time constraints, only 17 of 55 features were excavated, and no more than a handful of the 1100 posts were excavated. A few trips were made back to the site the following year with the help of volunteers, and approximately 80% of the area stripped by heavy machinery was mapped. Some of the features were trash features that consisted of a circular pit filled with food residues and pottery sherds. Evidence of a large circular structure or rotunda was found at the site. It was the social, political, and religious center for the inhabitants. A large quantity of the features was small, circular, semi-subterranean structures that were probably used as sleeping quarters on cold nights. Another structure found was warm weather structures. One major trash feature was found that had been deposited in a single episode and was burned during or after deposition. Numerous sherds were found in this pit, and a large number of reconstructable vessels were present. Ethnohistoric literature of the Southeast suggests that this feature was formed during a Busk or Green Corn ceremony. The ceremony has been described as the physical cleansing of the town.
ground_truth: Thomas Walker