Question: How many people are employed by the laboratory across from McKenzie, Maryland?

full_context: Document 1: Santa Susana Field Laboratory: The Santa Susana Field Laboratory is a complex of industrial research and development facilities located on a 2,668 acre portion of the Southern California Simi Hills in Simi Valley, California. It was used mainly for the development and testing of liquid-propellant rocket engines for the United States space program from 1949 to 2006, nuclear reactors from 1953 to 1980 and the operation of a U.S. government-sponsored liquid metals research center from 1966 to 1998. The site is located approximately 7 mi northwest from the community of Canoga Park and approximately 30 mi northwest of Downtown Los Angeles. Sage Ranch Park is adjacent on part of the northern boundary and the community of Bell Canyon along the entire southern boundary.
Document 2: Pen Mar, Maryland: Pen Mar is an unincorporated community in Washington County, Maryland, and Franklin County, Pennsylvania, United States. It is one of the border towns in the United States with a portmanteau name. Pen Mar came to prominence in the 20th century due to the construction of Pen Mar Park by the Western Maryland Railroad. The construction of the Pen Mar resort caused the area to become a destination for many people. While the resort has long been dismantled, the area still has some significance in Maryland, since it is the northern starting point for the Maryland section of the Appalachian Trail.
Document 3: Allegany Ballistics Laboratory: Allegany Ballistics Laboratory (ABL) located in Rocket Center, West Virginia, is a diverse industrial complex employing some 1,000 people across 1628 acre . The facility is a member of the Federal Laboratory Consortium and is operated by Alliant Techsystems (ATK) under contract with the Naval Sea Systems Command (NAVSEA).
Document 4: Sites Homestead: The Sites Homestead, also known as the Wayside Inn or the Sites Inn, is located near Seneca Rocks, West Virginia. The log house was built by Jacob Sites "circa" 1839 below the Seneca Rocks ridge. The house was expanded in the mid-1870s with a frame addition, remaining in the Sites family until it was acquired by the U.S. Forest Service in 1968 as part of Spruce Knob-Seneca Rocks National Recreation Area in Monongahela National Forest. The house had been used as a storage shed for some time and was in poor condition. It was restored by the Forest Service in the 1980s and became a temporary visitor center in 1992 after the Seneca Rocks visitor center burned. It is now part of the Seneca Rocks Discovery Center facility, operated by the Forest Service.
Document 5: Saturn V Dynamic Test Stand: Saturn V Dynamic Test Stand, also known as Dynamic Structural Test Facility, at the George C. Marshall Space Flight Center in Huntsville, Alabama is the test stand used for testing of the Saturn V rocket and the Space Shuttle prior to the vehicles' first flights. Designated building 4550, it stands 363 ft tall and is 98 ft square. NASA built the test stand in 1964 to conduct mechanical and vibrational tests on the fully assembled Saturn V rocket. Major problems capable of causing failure of the vehicle were discovered and corrected here.
Document 6: Lockheed Martin Advanced Technology Labs: Lockheed Martin Advanced Technology Laboratories is a department of Lockheed Martin, in the Electronic Systems business unit, located in Cherry Hill, NJ, with approximately 400 employees. Other locations include Westlake Village, CA, Atlanta, GA, Arlington, VA, and Vienna, VA. ATL specializes in advanced research and development and is analogous to the Lockheed Martin Aeronautics division's famous Skunk Works.
Document 7: Applied Physics Laboratory: The Johns Hopkins University Applied Physics Laboratory, commonly known as simply the Applied Physics Laboratory, or APL, located in Howard County, Maryland, near Laurel and Columbia, is a not-for-profit, university-affiliated research center (or UARC) employing 6,000 people. The Lab serves as a technical resource for the Department of Defense, NASA, and other government agencies. APL has developed numerous systems and technologies in the areas of air and missile defense, surface and undersea naval warfare, computer security, and space science and spacecraft construction. While APL provides research and engineering services to the government, it is not a traditional defense contractor, as it is a UARC and a division of Johns Hopkins University. APL is a scientific and engineering research and development division, rather than an academic division, of Johns Hopkins.
Document 8: Lost Cove, North Carolina: Lost Cove is a ghost town in Yancey County, North Carolina. The town was first settled by Morgan Bailey shortly before the Civil War. The town is located in the Poplar Gorge above the Nolichucky River on the Tennessee-North Carolina border. Originally, the settlement was supported by logging, railroading, moonshine-making, and farming industries. Several factors contributed to the town's abandonment including rough terrain, isolation, and the end of passenger railroad stops. In 1957, the last family left Lost Cove, leaving it deserted. Fires in 2007 burned most of the structures down. Today, the town is still accessible to those willing to hike. Visitors to the area come to see the cemetery, Swin Miller's rusted Chevy still laying in a ditch, and the three houses that remain.
Document 9: McKenzie, Maryland: McKenzie is an unincorporated community in Allegany County, Maryland, containing only a few houses, and mostly land. Its name is derived from a family which owned a large farm along the river bottom in the area. It is directly across from the Allegany Ballistics Laboratory in Rocket Center, West Virginia. The area used to be a railroad junction of the Patterson Creek Cutoff and the main B&O line. McKenzie is also the site of one of the first settlements in Allegany county, where many pieces of glass, metal, stone, and some coin have been found. In the fields of the river bottom, arrowheads and flint can be found, suggesting a possible Native American community at one time, similar to the Barton, Maryland site.
Document 10: Fort Ashby, West Virginia: Fort Ashby is a census-designated place (CDP) in Mineral County, West Virginia, USA, along Patterson Creek. It is part of the Cumberland, MD-WV Metropolitan Statistical Area. The population was 1,380 at the 2010 census. The community was originally chartered as Frankfort and then known as Alaska before it took the name of its well-known historic landmark.
Document 11: McKenzie Mountain Wilderness Area: The McKenzie Mountain Wilderness Area, an Adirondack Park unit of the Forest Preserve, lies in western Essex County in the towns of St. Armand, North Elba and Wilmington. In general, the Saranac River and Franklin Falls Pond border on the north; the Wilmington-Franklin Falls road, the Whiteface Mountain Memorial Highway and the west branch of the Ausable River form the eastern boundary; the Saranac Lake-Lake Placid Road, NY 86, forms the southern boundary; and the Saranac River forms the western boundary.
Document 12: U.S. Space &amp; Rocket Center: The U.S. Space & Rocket Center in Huntsville, Alabama is a museum operated by the government of Alabama, showcasing rockets, achievements, and artifacts of the U.S. space program. Sometimes billed as "Earth's largest space museum", astronaut Owen Garriott described the place as, "a great way to learn about space in a town that has embraced the space program from the very beginning."
Document 13: Lockheed Martin Advanced Technology Laboratories: Lockheed Martin Advanced Technology Laboratories (ATL) is a department of Lockheed Martin, located in Cherry Hill, New Jersey, with approximately 220 employees. Other locations include Westlake Village, California, Atlanta, Georgia, and Arlington, Virginia. ATL specializes in advanced research and development and is analogous to the Lockheed Martin Aeronautics division's famous Skunk Works.
Document 14: 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 15: Propulsion Wind Tunnel Facility: The Propulsion Wind Tunnel Facility, located at Arnold Engineering Development Complex, Arnold Air Force Base, Tennessee, holds three wind tunnels: the 16-foot transonic (16T), 16-foot supersonic (16S), and the aerodynamic 4-foot transonic (4T) tunnels. The facility is devoted to aerodynamic and propulsion integration testing of large-scale aircraft models. The tunnels are powered by a large compressor plant which allows the wind tunnels to run for extended periods of time. The test unit is owned by the United States Air Force and operated by Aerospace Testing Alliance.
ground_truth: some 1,000