Question: Which river system in Chilhowie, Virginia was the starting place for most Longhunters?

Context:
Thái Bình River
Thái Bình river (Vietnamese: Sông Thái Bình) is the name of the Thái Bình river system's main river in Northern Vietnam.
 This river system joining with Red River system have brought alluvium to create Red River Delta.
Blackback barb
the blackback barb ("Enteromius barnardi"), is a species of cyprinid fish native to Africa where it is known to occur in shallow, vegetated waters of the Zambezi River system, the Cunene River system and the Zambian portion of the Congo River system.
 This species can reach a length of 7 cm SL.
Red River system
The Red River system is a network of rivers surrounding the main river - Red River in North Vietnam.
 These branches of the system contribute to or receive water from Red River.
 Red River system, joining with the Thái Bình river system in the northeast, creates the Red River Delta - the second largest delta in Vietnam.
 Because of the close relation between Red River system and Thái Bình river system, the two system are known as the common name "Red and Thai Binh rivers system".
 Alluvium of the Red River system creates the central and south Red River Delta.
 Two banks of the rivers are protected by a great dyke system.
Holston River
The Holston River is a 136 mi river that flows from Kingsport, Tennessee, to Knoxville, Tennessee.
 Along with its three major forks (North Fork, Middle Fork and South Fork), it comprises a major river system that drains much of northeastern Tennessee, southwestern Virginia, and northwestern North Carolina.
 The Holston's confluence with the French Broad River at Knoxville marks the beginning of the Tennessee River.
Cotter River System
The Cotter River System (CRS) is located in the Australian Capital Territory and was constructed in 1912.
 A feature of the Namadgi National Park, the Cotter River System is one of two main sources for the Australian Capital Territory's water supply, the other being the Queanbeyan River located north of the Australian Capital Territory in New South Wales.
 Nevertheless, the Cotter River System is a larger catchment area and due to recent drought conditions the Queanbeyan River has been seen as obsolete in comparison.
Longhunter
A longhunter (or long hunter) was an 18th-century explorer and hunter who made expeditions into the American frontier wilderness for as much as six months at a time.
 Historian Emory Hamilton asserts that "The Long Hunter was peculiar to Southwest Virginia only, and nowhere else on any frontier did such hunts ever originate" although the term has been used loosely to describe any unofficial American explorer of the period.
 Most long hunts started in the Holston River Valley near Chilhowie, Virginia.
 The hunters came from there and the adjacent valley of the Clinch River, where they were land owners or residents.
 The parties of two or three men (and rarely more) usually started their hunts in October and ended toward the end of March or early in April.
Zambezi River System Action Plan
Zambezi River System Action Plan (ZACPLAN) is a multinational plan under the United Nations Environment Program (UNEP) to incorporate effective use, and management of the Zambezi River system.
 ZACPLAN encompasses eight countries: Angola, Botswana, Malawi, Mozambique, Namibia, Tanzania, Zambia, and Zimbabwe.
 The Zambezi river basin is used by all these South African countries; this plan attempts to manage resources collectively amongst, and between SADCC Nations to reasonably meet national, and international goals for water resources.
 Due to the immense river basin formed by the Zambezi River together with its tributaries, the Zambezi River System Plan is a culmination of a UN commission, to focus on the projection that the demand for the basins water resources would increase.
 This competition creates negative utilization, and inefficient use of resources for all these countries in a profitable manner.
Pearl River (China)
The Pearl River, also known by its Chinese name Zhujiang and formerly often known as the Canton River , is an extensive river system in southern China.
 The name "Pearl River" is also often used as a catch-all for the watersheds of the Xi ("West"), Bei ("North"), and Dong ("East") rivers of Guangdong.
 These rivers are all considered tributaries of the Pearl River because they share a common delta, the Pearl River Delta.
 Measured from the farthest reaches of the Xi River, the Pearl River system is China's third-longest river, 2400 km , after the Yangtze River and the Yellow River, and second largest by volume, after the Yangtze.
 The 409480 km2 Pearl River Basin (珠江流域 ) drains the majority of Liangguang (Guangdong and Guangxi provinces), as well as parts of Yunnan, Guizhou, Hunan and Jiangxi in China; it also drains northern parts of Vietnam's Northeast Cao Bằng and Lạng Sơn provinces.
Thái Bình river system
The Thái Bình river system is one of the two major river systems in the Red River Delta, Vietnam.
 (the other one is the Red River system).
 The system consists of 8 rivers flowing in northern Vietnam.
 This system joining with Red River system creates the Red River Delta.
Eastern freshwater cod
Eastern freshwater cod ("Maccullochella ikei"), also known as eastern cod or Clarence River cod, are a large predatory freshwater fish of the "Maccullochella" genus and the family Percichthyidae, that occur in the coastal Clarence River system of north-eastern New South Wales.
 Eastern freshwater cod are closely related to the Murray cod of the Murray-Darling River system, and are considered an icon of the Clarence River system.

Answer: Holston River