The Mills-Baker Construction Company purchased the Hawks Homestead, Section 7, Township 33 north. Range 79 West, in 1919 to excavate the sand and gravel from the flood plain of the North Platte River. The men who worked for the company needed a place to live and the company had their surveyor, J.B Cleary, lay out and plat lots for home sites. In 1919 the company platted the Mills-Baker Addition to the City of Casper, which set out about ten blocks near the Chicago and North Western Railroad. In 1920 there was a second Mills-Baker Addition and later a third addition, the three of which comprised an area from the railroad to the Mills School and from First Street to Fourth Street. The distance between Mills and Casper at the time was over a half mile, but the plats were drawn up as annexations to Casper. However, there was no real intent to become part of Casper.

The area boomed, and reports were that as many as five hundred people lived in the additions in 1921. The land sold quickly, houses were built, and everyone was busy. There was so much activity that by 1921 the people in the area decided there was need for some local government, and, as outlined above, the move for incorporation as a town began.