During the years 1915-1920 Harleigh Holmes, while working in Carbondale, Colorado, had an idea for a new kind of vehicle mechanism-four-wheel drive. Cars and trucks had only been around for about 20 years in 1916. Holmes had the foresight to patent his ideas for a four-wheel drive and a front-wheel drive, and he founded Holmes Motor Company in Littleton to build four-wheel drive trucks.
It did not take long before the reputation of the truck began to grow. In April 1921, a heavy snow caused problems for those living in the foothills near Littleton. One man, trapped about three miles into Deer Creek Canyon, was in dire circumstances due to the cold. No one could get to him. Harleigh Holmes heard of the man's plight and decided to help. He and eight of his employees drove a Holmes truck up Deer Creek Canyon, plowing through several four-foot drifts of snow on a vertical incline. They left the road and broke new ground to reach the trapped man, then turned around and brought him out, without any trouble.
1921, Holmes obtained a loan from Plains Iron Works of Denver. The name of the motor company was changed to Plains Motor Corporation and operations were moved to Denver. The Holmes truck was re-named the Plains four-wheel drive truck. By the summer of 1921, the company had diversified into offering the Holmes system for Fords, converting the Ford trucks into four-wheel drive vehicles. This was a lucrative step for Holmes. Discussions with N.S. Clark of Vancouver, Canada produced an order for 500 Holmes systems and Mr. Clark purchased the Canadian patent rights to the four-wheel drive system. Demonstrations at the Platte River in September, 1921 showed that the Holmes system fitted to a Ford could navigate through deep sand and water hauling a load, while similar vehicles quickly became mired.
In 1922, wealthy miners Alfred E. Coleman and his brother George bought 51% of the Plains Motor Corporation and Harleigh Holmes moved the plant back to Littleton. The Colemans also bought the creamery building on South Nevada Street in Littleton for the new vehicle operations. Holmes retained a senior position in the new company.
About thirty men were employed in the Coleman plant in the 1920s. Harleigh Holmes utilized an innovative form of marketing the trucks, called Holmes Trucks in 1924. He simply demonstrated how well the trucks worked. Often he would stop to pull someone out of the mud or snow. His employees were instructed to do the same, and the reputation of the trucks became known throughout the area. One anecdote reported by the Littleton Independent (March 14, 1924) told of a Pierce Arrow truck fully loaded with groceries that had become mired in the mud. A Holmes truck returning from Denver loaded with 3 tons of material stopped to help. Without unloading, the driver of the Holmes hooked the two trucks together and the Holmes pulled out the Pierce Arrow "with little effort.