Question: This National Grassland located in Morton County Kansas hosts which monument dedicated to the meeting of states?

full_context: Document 1: 8 Mile Corner: 8 Mile Corner is a monument in the Cimarron National Grassland dedicated to the tri-point (a place where three states meet) of Kansas, Colorado, and Oklahoma. This point is also the meeting point for three distinct regions of America - the Western United States (Colorado), Midwestern United States (Kansas) and South Central United States (Oklahoma). The landmark is a windmill with the three states' abbreviated names on the blades. The windmill monument was built in 1903. In 1990, satellite images showed the actual meeting place to be several feet away from the monument. A brass plate in the ground marks this. The site is approximately 8 miles west of Elkhart, Kansas on mostly unpaved State Line Road.
Document 2: Tallgrass Prairie Preserve: The Tallgrass Prairie Preserve, located in Osage County, Oklahoma near Foraker, Oklahoma, is owned and managed by The Nature Conservancy. It is protected as the largest tract of remaining tallgrass prairie in the world. The preserve contains 39000 acre owned by the Conservancy and another 6000 acre leased in what was the original tallgrass region of the Great Plains that stretched from Texas to Manitoba.
Document 3: Buffalo Gap National Grassland: Buffalo Gap National Grassland is a National Grassland located primarily in southwestern South Dakota, United States. It is also the second largest National Grassland, after Little Missouri National Grassland in North Dakota. Characteristics of the grasslands include mixed prairie and chalky badlands. The grassland is managed by the U.S. Forest Service and is a division of Nebraska National Forest. In descending order of land area it is located in parts of Fall River, Pennington, Jackson, and Custer counties.
Document 4: Wagon Mound, New Mexico: Wagon Mound is a village in Mora County, New Mexico, United States. It is named after and located at the foot of a butte called Wagon Mound, which was a landmark for covered wagon trains and traders going up and down the Santa Fe Trail and is now Wagon Mound National Historic Landmark. The shape of the mound is said to resemble a Conestoga wagon. As of the 2000 census, the village population was 369. It was also called Santa Clara for many years. The village, with brightly painted houses and several stores and shops, is located on the plains of northeastern New Mexico. Interstate 25, which skirts the west side of town, gives a view of the majority of the town. Wagon Mound is not growing rapidly, but it has seen new construction along I-25, with new buildings on the northeast side of town as well.
Document 5: Tri-State Peak: Tri-State Peak is a mountain located in the Cumberland Gap National Historical Park, near the "saddle" of the gap. It gets its name from being on the tri-point of the states of Kentucky, Tennessee, and Virginia.
Document 6: Tri-State district: The Tri-State district was an historic lead-zinc mining district located in southwest Missouri, southeast Kansas and northeast Oklahoma. The district produced lead and zinc for over 100 years. Production began in the 1850s and 1860s in the Joplin - Granby area of Jasper and Newton counties of southwest Missouri and continued until the closure of the Picher, Oklahoma mines in 1967. The tri-state district includes three mining-related Superfund sites: the Tar Creek Superfund site in Oklahoma, and two others in Missouri and Kansas.
Document 7: McClellan Creek National Grassland: McClellan Creek National Grassland is a National Grassland located in southern Gray County, Texas, United States. It was purchased with the goal of restoring badly eroded land to its natural state. The grassland is administered by the U.S. Forest Service together with Cibola National Forest and Black Kettle, Kiowa, and Rita Blanca National Grasslands, from common headquarters located in Albuquerque, New Mexico. The grassland is part of the combined Black Kettle and McClellan Creek Ranger District with offices in Cheyenne, Oklahoma.
Document 8: Cimarron National Grassland: Cimarron National Grassland is a National Grassland located in Morton County, Kansas, United States, with a very small part extending eastward into Stevens County. Cimarron National Grassland is located near Comanche National Grassland which is across the border in Colorado. The grassland is administered by the Forest Service together with the Pike and San Isabel National Forests and the Comanche National Grassland, from common headquarters located in Pueblo, Colorado. There are local ranger district offices in Elkhart, Kansas. The grassland is the largest area of public land in the state of Kansas.
Document 9: Wagon Bed Spring (Kansas): Wagon Bed Spring (also Lower Spring or Lower Cimarron Spring), located in Grant County, Kansas, United States, was an important watering spot on the Cimarron Cutoff of the Santa Fe Trail. The flow of the spring came from an outcropping of the Ogallala Formation. Center pivot irrigation adjacent to the spring resulted in lowering of the water table and the spring ceased to flow in the 1960s. A number of small artifacts dating from the days of the Santa Fe Trail have been recovered from lands near the spring which were used by both American Indians and wagon trains as a campground. The name "wagon bed" dates from later use of an old wagon bed as a trough to collect water from the spring. There is a foundation on the site of an ice house. Floods have changed the course of the Cimarron River; the site of the spring is now in the bed of the river rather than on its bank as it was in the days of the Santa Fe Trail.
Document 10: Miller Brothers 101 Ranch: The Miller Brothers 101 Ranch was a 110000 acre cattle ranch in the Indian Territory of Oklahoma before statehood. Located near modern-day Ponca City, it was founded by Colonel George Washington Miller, a veteran of the Confederate Army, in 1893. The 101 Ranch was the birthplace of the 101 Ranch Wild West Show and one of the early focal points of the oil rush in northeastern Oklahoma. It was the largest diversified farm and ranch in America at the time. Bill Pickett's grave and the White Eagle Monument are located on the ranch grounds. The location of the former working cattle ranch was subdivided and all of its buildings destroyed. An 82 acre area of the ranch is a National Historic Landmark.
Document 11: Sheyenne National Grassland: Sheyenne National Grassland is a National Grassland located in southeastern North Dakota in the United States, comprising 70446 acre of public land amid 64,769 acre of privately owned land in a region of sandy soils in the vicinity of the Sheyenne River in Ransom and Richland Counties. It is the only National Grassland in the tallgrass prairie region of the U.S. The grassland provides habitat for the largest population of greater prairie chickens in North Dakota, as well as the Dakota skipper butterfly, the western prairie fringed orchid, and numerous ferns, as well as grazing land for approximately 83 cattle ranchers.
Document 12: Eleven Mile Corner, Arizona: Eleven Mile Corner, Arizona, is a former settlement and Rural Postal Station now largely considered to be an unincorporated portion of the city of Casa Grande, with which it now shares a common zip code. The area was so named due to its location being (by old mile markers and former city boundaries) 11 miles to the east of Casa Grande, 11 miles north of Eloy, Arizona, and 11 miles Southwest of Coolidge, Arizona.
Document 13: Little Missouri National Grassland: Little Missouri National Grassland is a National Grassland located in western North Dakota, USA. At 1028051 acres , it is the largest grassland in the country. Enclaved within its borders is Theodore Roosevelt National Park, which is managed by the National Park Service (and therefore not included in the preceding statistics). The Little Missouri National Grassland was once a part of the Custer National Forest, but is now a part of the Dakota Prairie Grasslands, a National Forest unit consisting entirely of National Grasslands. A predominant feature of the grassland is colorful and beautiful badlands, a rugged terrain extensively eroded by wind and water. It is a mixed grass prairie, meaning it has both long and short grass.
Document 14: Three Entrance Cave Archeological District: Three Entrance Cave Archeological District is a 9 acre archeological site in Cimarron County, Oklahoma, near Kenton, that was listed on the National Register of Historic Places in 1978. Its specific location is not disclosed by the National Register. It includes two contributing sites, at least one being a prehistoric camp location. It was listed on the National Register for its potential to yield information in the future.
Document 15: Comanche National Grassland: Comanche National Grassland is a National Grassland located in southeastern Colorado, United States. It is the sister grassland of Cimarron National Grassland and contains both prairie grasslands and canyons. It is separated into two sections, each operated by a local ranger district, one of which is in Springfield and the other of which is in La Junta. The grassland is administered by the Forest Service together with the Pike and San Isabel National Forests, and the Cimarron National Grassland, from common headquarters located in Pueblo, Colorado.
ground_truth: 8 Mile Corner