In June of 1863, newlyweds Lafayette and Mary E. Miller arrived in Burlington, Colorado (later known as Longmont) by wagon train from the East. Soon afterward they left Burlington to operate a stage stop along the Overland Trail between Denver and Cheyenne at the present site of the Coal Creek Farm. The couple then acquired a farm in the Lafayette area through the Homestead Act, and moved there in 1871.

In 1874, the Millers moved to Boulder, where Lafayette worked as a butcher and served as both a town trustee and a volunteer fireman before dying suddenly in 1878. After that, Mrs. Miller moved back to the farm with her six small children and managed it alone. The farm prospered in the succeeding years, and the following description appeared in the Boulder County Herald in 1886:

Among the best conducted large farms in Boulder County is that carried on and managed by Mrs. Mary Miller, about two miles east of Louisville. The farm contains 1,280 acres, all under fence, about 1/2 of which is under plow and first class meadow, the balance in pasture. Large crops of oats, corn, and wheat are raised and great stacks of upland hay are plentiful in the field. Horses and cattle, of which there are about 100 or more head, are permitted to roam over the field during the winter and are in fine condition as the large enclosure affords ample feed for all with scarcely any care. Hogs by the score may be seen around the field near the barn. They all show signs of well-filled corn cribs.