Area 51 Nellis Bombing Range Test Site airport (KXTA) on the north of the Area 51 USAF military installation. The lake at elevation is approximately from north to south and from east to west at its widest point. Located within the namesake Groom Lake Valley portion of the Tonopah Basin, the lake is south of Rachel, Nevada. The origin of the Area 51 name is unclear. The most accepted comes from a grid numbering system of the area by the Atomic Energy Commission (AEC); while Area 51 is not part of this system, it is adjacent to Area 15. Another explanation is
Oklahoma State Highway 51 area. In Sand Springs, SH-51 crosses the Arkansas River with SH-97 before merging onto the Sand Springs Expressway (U.S. Highway 412/U.S. Highway 64). When this freeway ends at I-244 near downtown Tulsa, Highway 51 merges onto I-244 southbound only to exit one mile (1.6 km) later, where it overlaps US-64/US-75. This freeway is actually Interstate 444, but the interstate designation is not shown on signs. After one more mile, SH-51 leaves the interstate with US-64 and becomes the Broken Arrow Expressway, a freeway running northwest-southeast through Tulsa which is known as "The BA" by locals and local media. US-64 leaves