By the time Grand Junction was three years old, it had become apparent to its citizens that they needed a good coal supply if the town were to grow and prosper. Early in 1884 an experienced coal miner named George W. Smith set out to locate a mine that would adequately supply the city's needs. In a remote and unexplored canyon of the Book Cliffs twelve miles from town he found a huge body of coal. Smith and several other men developed the discovery into what became known as the Book Cliff Mine. Two years later another coal mine was opened a half a mile north of the Book Cliff coal mine; it was called the Grand Valley Mine. Both mines were purchased by William Thomas Carpenter in the summer of 1888, and under his Grand Valley Fuel Company they were improved and further developed. He built the Little Book Cliff Railway to serve the mines. A small community of miners took root nearby. The U.S. post office established a branch there during June 1890, officially dubbing the settlement Carpenter, Colorado.