The 1820 Missouri Compromise declared no slavery would be allowed in states admitted from the Louisiana Purchase above 36°30′ north latitude.

West of the Caprock Escarpment and North and South of the Canadian River breaks, the surface of the Llano Estacado is rather flat.

North of Amarillo lies Lake Meredith, a reservoir created by Sanford Dam constructed on the main stem of the Canadian River.

The freeway passes through Deaf Smith, Oldham, Potter, Carson, Gray, Donley, and Wheeler Counties.

[2] About 92.3% of inhabitants claimed native birth, and 8.9% were veterans of the United States armed forces; 49.9% of the population was male, and 50.1% was female.