Question: When did the state containing the Pawnee National Grasslands become part of the US?

full_context: Document 1: Oklahoma: With 39,000 acres (158 km2), the Tallgrass Prairie Preserve in north-central Oklahoma is the largest protected area of tallgrass prairie in the world and is part of an ecosystem that encompasses only 10 percent of its former land area, once covering 14 states. In addition, the Black Kettle National Grassland covers 31,300 acres (127 km2) of prairie in southwestern Oklahoma. The Wichita Mountains Wildlife Refuge is the oldest and largest of nine national wildlife refuges in the state and was founded in 1901, encompassing 59,020 acres (238.8 km2).
Document 2: Tarryall Creek: Tarryall Creek is a tributary of the South Platte River, approximately long, in Park County in central Colorado in the United States. It drains a rural portion of north and central South Park, an intermontane grassland in the Rocky Mountains southwest of Denver. It rises in the high Rockies in several forks along the Continental Divide in the Pike National Forest southwest of Boreas Pass. It descends to the southwest through a short canyon, emerging into South Park near Como, Colorado. It crosses U.S. Highway 285 east of Red Hill Pass northeast of Fairplay, the county seat of Park County, then meanders towards the southeast, joining the South Platte from the east in the southeastern corner of South Park.
Document 3: Utah Territory: The Territory of Utah was an organized incorporated territory of the United States that existed from September 9, 1850, until January 4, 1896, when the final extent of the territory was admitted to the Union as the State of Utah, the 45th state.
Document 4: History of Colorado: The United States Congress passed an enabling act on March 3, 1875, specifying the requirements for the Territory of Colorado to become a state. On August 1, 1876 (28 days after the Centennial of the United States), U.S. President Ulysses S. Grant signed a proclamation admitting the state of Colorado to the Union as the 38th state and earning it the moniker ``Centennial State ''. The borders of the new state coincided with the borders established for the Colorado Territory.
Document 5: Geography of the United States: The Great Plains lie west of the Mississippi River and east of the Rocky Mountains. A large portion of the country's agricultural products are grown in the Great Plains. Before their general conversion to farmland, the Great Plains were noted for their extensive grasslands, from tallgrass prairie in the eastern plains to shortgrass steppe in the western High Plains. Elevation rises gradually from less than a few hundred feet near the Mississippi River to more than a mile high in the High Plains. The generally low relief of the plains is broken in several places, most notably in the Ozark and Ouachita Mountains, which form the U.S. Interior Highlands, the only major mountainous region between the Rocky Mountains and the Appalachian Mountains.
Document 6: Grasslands National Park: Grasslands National Park is a Canadian national park located near the village of Val Marie, Saskatchewan, and one of 44 national parks and park reserves in Canada's national park system (though one of only two in Saskatchewan itself). This national park is north from the American state of Montana and lies adjacent to the international boundary.
Document 7: Montana: Under Territorial Governor Thomas Meagher, Montanans held a constitutional convention in 1866 in a failed bid for statehood. A second constitutional convention was held in Helena in 1884 that produced a constitution ratified 3:1 by Montana citizens in November 1884. For political reasons, Congress did not approve Montana statehood until 1889. Congress approved Montana statehood in February 1889 and President Grover Cleveland signed an omnibus bill granting statehood to Montana, North Dakota, South Dakota and Washington once the appropriate state constitutions were crafted. In July 1889, Montanans convened their third constitutional convention and produced a constitution acceptable by the people and the federal government. On November 8, 1889 President Benjamin Harrison proclaimed Montana the forty-first state in the union. The first state governor was Joseph K. Toole. In the 1880s, Helena (the current state capital) had more millionaires per capita than any other United States city.
Document 8: Ohio: On February 19, 1803, U.S. President Thomas Jefferson signed an act of Congress that approved Ohio's boundaries and constitution. However, Congress had never passed a resolution formally admitting Ohio as the 17th state. The current custom of Congress declaring an official date of statehood did not begin until 1812, with Louisiana's admission as the 18th state. Although no formal resolution of admission was required, when the oversight was discovered in 1953, Ohio congressman George H. Bender introduced a bill in Congress to admit Ohio to the Union retroactive to March 1, 1803, the date on which the Ohio General Assembly first convened. At a special session at the old state capital in Chillicothe, the Ohio state legislature approved a new petition for statehood that was delivered to Washington, D.C. on horseback. On August 7, 1953 (the year of Ohio's 150th anniversary), President Eisenhower signed a congressional joint resolution that officially declared March 1, 1803, the date of Ohio's admittance into the Union.
Document 9: Pawnee National Grassland: Pawnee National Grassland is a United States National Grassland located in northeastern Colorado on the Colorado Eastern Plains. The grassland is located in the South Platte River basin in remote northern and extreme northeastern Weld County between Greeley and Sterling. It comprises two parcels totaling largely between State Highway 14 and the Wyoming border. The larger eastern parcel lies adjacent to the borders of both Nebraska and Wyoming. It is administered in conjunction with the Arapaho-Roosevelt National Forest from the U.S. Forest Service office in Fort Collins, Colorado, with a local ranger district office in Greeley.
Document 10: Tallgrass Aspen Parkland: The Tallgrass Aspen Parkland is a Conservation area located in northeastern Manitoba and northwestern Minnesota. The area is characterized by a mosaic of habitat types, including tallgrass prairie, aspen woodland, sedge meadow wetlands, riparian woodland, and oak savannah. A number of endangered and threatened species occur in the area, including the Western Prairie Fringed Orchid and Dakota Skipper. One of Minnesota's only wild elk herds utilizes the area as well.
Document 11: Colorado Territory: Colorado Territory was officially organized by Act of Congress on February 28, 1861, out of lands previously part of the Kansas, Nebraska, Utah, and New Mexico territories. Technically the territory was open to slavery under the Dred Scott Decision of 1857, but the question was rendered moot by the impending American Civil War and the majority pro-Union sentiment in the territory. The name "Colorado" was chosen for the territory. It had been previously suggested in 1850 by Senator Henry S. Foote as a name for a state to have been created out of present-day California south of 35° 45'. To the dismay of Denverites, the town of Colorado City was designated the first territorial capital, quickly succeeded by Golden. Denver eventually became the temporary territorial capital, but was not designated the permanent capital until 1881, five years after Colorado became a state.
Document 12: Konza Prairie Biological Station: The Konza Prairie Biological Station is a 3,487-hectare (8,616 acre, 13.5 sq mi) preserve of native tallgrass prairie in the Flint Hills of northeastern Kansas. It is located south of Manhattan, Kansas and its southern boundary parallels Interstate 70. A scenic overlook exists on the preserve's eastern boundary along K-177. "Konza" is an alternative name for the Kansa or Kaw Indians who inhabited this area until the mid-19th century.
Document 13: Great Plains: The Great Plains is the broad expanse of flat land (a plain), much of it covered in prairie, steppe and grassland, that lies west of the Mississippi River tallgrass prairie states and east of the Rocky Mountains in the United States and Canada. This area covers parts, but not all, of the states of Colorado, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas, and Wyoming, and the Canadian provinces of Alberta, Manitoba and Saskatchewan. The region is known for supporting extensive cattle ranching and dry farming.
Document 14: Colorado Territory: The movement to create a territory within the present boundaries of Colorado followed nearly immediately. Citizens of Denver and Golden pushed for territorial status of the newly settled region within a year of the founding of the towns. The movement was promoted by William Byers, publisher of the Rocky Mountain News, and by Larimer, who aspired to be the first territorial governor. In 1859, settlers established the Territory of Jefferson, and held elections, but the United States Congress did not recognize the territory, and it never gained legal status.
Document 15: Utah Territory: Territory of Utah Organized incorporated territory of the United States ← 1850 -- 1896 → → → → → Territorial coat of arms (1876) The Utah Territory upon its creation. Modern state boundaries are shown for reference. Capital Fillmore (1851 -- 1856) Salt Lake City Government Organized incorporated territory Governor 1851 -- 1858 Brigham Young 1893 -- 1896 Caleb Walton West Legislature Utah Territorial Assembly History State of Deseret 1849 Utah Organic Act September 9, 1850 Colorado Territory formed February 28, 1861 Nevada Territory formed March 2, 1861 Wyoming Territory formed July 25, 1868 Statehood January 4, 1896
ground_truth: August 1, 1876
sub_queries: Which state is Pawnee National Grassland located? Answer: Colorado
when did Colorado become part of the united states Answer: August 1, 1876