1858 – The Picacho Mine, about 8 miles south of New Idria, is discovered by Wiley Williams and Edward C. Tully.
1858, January 25 – Eleven men form the New Idria Mining Company.
1858, February – Luciano, the man employed as a hunter is attacked by a large Grizzly bear. He injured himself getting away from the bear.
1858, April – J. T. Myers is hired to dig a tunnel at New Idria. The tunnel is to be 100 feet long, four and one-half feet wide, and six and one-half feet high. Myers and four other laborers received $21.00 per yard for their work and complete the tunnel in three months. It becomes known as the Myers Tunnel.
1858, October – The company has ninety employees working in and around the mines. They built new roads from the Aurora Mine to the upper sawmill and have commenced construction of tunnels in the Aurora and San Carlos Mines.
1858 – William McGarrahan sues New Idria claiming that the mine is located on the Panoche Grande, a Spanish land grant that he purchased from Vicente Gómez. This legal battle continued for 36 years, becoming the longest in United States history and eventually involved the U.S. Congress, Presidential action, and finally ended with the death of McGarrahan in April 1894.
