scales and in varying locations have been undertaken on the Comstock Lode in every decade since its discovery. There was a particular flurry of activity, including major surface mining operations by the Houston Oil and Mineral Company followed by United Mining in the late 1970s and early 1980s. This activity paralleled a rapid and substantial rise in the price of gold and silver, which was unpegged from the dollar by President Nixon in 1971. Today, the Comstock Lode is being explored by Comstock Mining Inc. of Virginia City, Nevada, which has consolidated control of approximately 70% of Comstock mining claims. On September 30, 2012, Comstock Mining Inc. returned gold and silver production to the Comstock with its first pour of doré bullion and continues surface mining in lower Gold Hill. Legacy Nevada is commonly called the "Silver State" because of the silver produced from the Comstock Lode. However, since 1878, Nevada has been a relatively minor silver producer, with most subsequent bonanzas consisting of more gold than silver. In 1900, Jim Butler discovered Nevada's second largest silver strike in Tonopah, Nevada. Nevada is currently ranked as the second largest producer of silver in the United States. Nevada's leading silver producer is the Rochester Mine in Pershing County. This mine ranks behind the Greens Creek mine in Alaska, the largest producer of silver in the US. According to Dan De Quille, a journalist of the period, "the discovery of silver undoubtedly deserves to rank in merit above the discovery of the gold mines of California, as it gives value to a much greater area of territory and furnishes employment to a much larger number of people". The latter quarter of the nineteenth century and first decade of the twentieth employed miners and mining technology invented on the Comstock, throughout various other mining camps in the west. Deep underground, hard rock mining was a constantly evolving development for the miners and their companies, and the tactics developed on the Comstock became famous within the mining industry, worldwide. Two U.S. Navy ships have been named for the Comstock Lode. The first was the USS Comstock (LSD-19) which was launched in 1945 and the second is the USS Comstock (LSD-45) which was launched in 1988. Fortunes made Four Irishmen, John William Mackay, James Graham Fair, James C. Flood and William S. O'Brien formed a business partnership in 1869 known as the "Bonanza Firm," which