Manufactured gas appeared at Denver (1871) with the arrival of the railroad. Eastern money, attracted to mining, turned to gas, coke and coal-tar, at Coal Creek (1879), Leadville (1883), Crested Butte (1884), Pueblo (1884), Colorado Springs (1889), Trinidad (ca. 1889) and Sterling (ca. 1891) and Georgetown (pre-1894),

Opposition and ensuing consolidation was present at Denver (1883-1889), coal-tar chemical industry (1887), Pintsch railway oil gas (1891), and creosote wood treatment (1908). Oil shale development resulted in more spilled, leaked and dumped PAH toxic chemicals. A brief invasion of natural gas, from the Wellington field of northern Colorado, peaked and fizzled about 1928, but sufficient supplies from Amarillo, Texas turned the Front Range corridor by 1934. Carburetted water gas plants continued to operate elsewhere until the 1950s.

Leon P. Lowe’s forerunner of the Pacific Coast Oil Gas process was first introduced by the inventor, with eastern money, at Colorado Springs, in 1889.

Eastern gas money again focused on Colorado with a rush of holding company colonization by CWG, from 1913-1917, providing the first illuminating gas to several smaller cities. The author has discovered 65 gas works and associated coal-tar sites of Colorado. Denver leads with 15, followed by Pueblo with five.