Question: Operation Roller Coaster was a series of nuclear tests conducted at a reservation located in what county?

Context paragraphs:
Operation Storax: Operation Storax was a series of 47 nuclear tests conducted by the United States in 1962-1963 at the Nevada Test Site.  These tests followed the "Operation Fishbowl" series and preceded the "Operation Roller Coaster" series.

Operation Roller Coaster: Operation Roller Coaster was a series of 4 nuclear tests conducted by the United States in 1963 at the Nevada Test Site.  These tests followed the "Operation Storax" series and preceded the "Operation Niblick" series.

Operation Niblick: The United States's Niblick nuclear test series was a group of 41 nuclear tests conducted in 1963–1964.  These tests followed the "Operation Roller Coaster" series and preceded the "Operation Whetstone" series.

1986–88 French nuclear tests: The 1986–1988 French nuclear tests were a group of 24 nuclear tests conducted between 1986 and 1988.  These tests followed the "1983–85 French nuclear tests" series and preceded the "1989–91 French nuclear tests" series.

1989 Soviet nuclear tests: The Soviet Union's 1989 nuclear test series was a group of 7 nuclear tests conducted in 1989.  These tests followed the "1988 Soviet nuclear tests" series and preceded the "1990 Soviet nuclear tests" series.

1966–70 French nuclear tests: The France's 1966–1970 nuclear test series was a group of 22 nuclear tests conducted in 1966–1970.  These tests followed the "In Ekker series, French nuclear tests" series and preceded the "1971–74 French nuclear tests" series.

Nevada Test Site: The Nevada National Security Site (N2S2),(though the abbreviation NNSS is still used), previously the Nevada Test Site (NTS), is a United States Department of Energy reservation located in southeastern Nye County, Nevada, about 65 miles (105 km) northwest of the city of Las Vegas.  Formerly known as the Nevada Proving Grounds, the site was established on 11 January 1951 for the testing of nuclear devices, covering approximately 1,360 square miles (3,500 km) of desert and mountainous terrain.  Nuclear weapons testing at the Nevada Test Site began with a 1-kiloton-of-TNT (4.2 TJ) bomb dropped on Frenchman Flat on 27 January 1951.  Many of the iconic images of the nuclear era come from the NTS.  NNSS is operated by National Security Technologies, LLC, a joint venture of Northrop Grumman, AECOM, CH2M Hill, and Babcock & Wilcox.

1987 Soviet nuclear tests: The Soviet Union's 1987 nuclear test series was a group of 24 nuclear tests conducted in 1987.  These tests followed the "1985 Soviet nuclear tests" series and preceded the "1988 Soviet nuclear tests" series.

In Ekker series, French nuclear tests: The France's In Ekker nuclear test series was a group of 14 nuclear tests conducted in 1961-1966.  These tests followed the "Reggane series, French nuclear tests" series and preceded the "1966–70 French nuclear tests" series.

1988 Soviet nuclear tests: The Soviet Union's 1988 nuclear test series was a group of 16 nuclear tests conducted in 1988.  These tests followed the "1987 Soviet nuclear tests" series and preceded the "1989 Soviet nuclear tests" series.

Supporting paragraphs: Operation Roller Coaster Nevada Test Site
Answer: Nye County