Gilsonite, a lightweight, glossy black, bituminous asphaltite, is the primary hydrocarbon mined in Utah. It has been mined commercially only in northeastern Utah, where it occurs south of Vernal and Roosevelt in parallel vertical veins that cut across the Uinta Basin. It is believed to be a solid residue of petroleum, and was initially named uintaite in 1885 by W.P. Blako. The mineral was later named in honor of Samuel H. Gilson, a Salt Laker who brought it into prominence for commercial uses such as in paints and varnishes, and in other building products.
Gilsonite has been produced since the 1880s, and in 1886 claims were filed by Gilson, Burt Seaboldt, and others. Seaboldt experimented with the substance and observed that it was resistant to acids and moisture. He succeeded in having his mining claims removed from the Uintah Reservation. In 1888 the Gilsonite Manufacturing Company was organized in Salt Lake City. Reportedly, at that time some 3,000 tons of Gilsonite were shipped to Price and sold for $80.00 a ton. In 1889 the company sold out to the Gilson Asphaltum Company of Missouri, and by 1900 the Gilson Asphaltum Company of New Jersey had acquired the property.
As with metals and coal mining, efficient transportation proved necessary to the commercial development of Gilsonite. The Uintah Railway Company was begun in 1903 by the Barber Asphalt Paving Company. The Barber Company was owned by the General Asphalt Company, which was itself owned by the Gilson Asphaltum Company. In 1902 the Barber Company began the development of the Black Dragon vein, and in 1904 the Uintah Railway completed its fifty-three-mile narrow-gauge railroad to the mines. The line ran across the Book Cliffs from Dragon, Utah, to Mack, Colorado, where it connected with the Denver and Rio Grande Western main line. Wagon freighting costs in 1900 were reported to be from $10.00 to $15.00 per ton to carry the ore to the railhead, with rail costs at $10.00 per ton to Chicago or St. Louis. In 1911, the railway was extended to Watson, then four miles southwest to the Gilsonite mine at Rainbow. A wagon road called the Uintah Toll Road was built to carry freight and passengers over the sixty miles between Vernal, Fort Duchesne, and Dragon.