The Covenant Assault on the Great Plains region of North America was embarked on in an attempt to cut the U.S. and Canada down the middle in an attempt to make it difficult for the UNSC to transport supplies from the west coast to the east coast. The assault was to be two pronged, with the northern half landing in the Canadian arctic and the southern half landing on the coast of Texas. The southern force rolled north through Texas, destroying all UNSC forces in its path. After San Antonio and Dallas, the sites of two UNSC defeats, the next thing in the Covenants way were two UNSC bases in southwest Oklahoma, Fort Sill Army Base and Altus Air Force Base. Covenant forces under the Brute Chieftain Tarkanus chose focus their efforts on the base at Fort Sill, the home of a considerable amount o