Technical Report

(PDF, 3MB) RESOURCE DATA EVALUATION SOUTH MOUNTAIN PROPERTY
SOUTH MOUNTAIN MINING DISTRICT
OWYHEE COUNTY, IDAHO

(PDF, 9MB) Appendices A, B, C

(PDF, 9MB) Appendices D, E

See news items:

• 5/21/2008: Thunder Mountain Gold Announces the Completion of a Technical Report on its South Mountain Property
• 10/9/2007: Thunder Mountain Resources Acquires 100% Interest in Historic Idaho Zinc-Silver-Lead-Copper-Gold Mine
• 6/28/2007: Thunder Mountain Gold Forms Subsidiary Corporation and Executes Purchase Agreement for South Mountain Mines, Inc.

The South Mountain Mining District was discovered and worked in the late 1800s for high-grade silver ore mined from oxidized lead-silver veins. Mineralization on the patented claims consists of skarn-hosted polymetallic sulfide ore bodies hosted in a Paleozoic and/or Mesozoic carbonate unit. The principal metals historically recovered from the South Mountain property were silver, zinc, lead, copper, and gold. The property was mined underground extensively during World War II, and smelter records for "crude ore shipments" from the mine during the periods 1940 through 1954 showed a total of 53,642 tons of ore that contained 15,593,000 pounds of zinc (14.5%), 2,562,300 pounds of lead (2.4%), 1,485,200 pounds of copper (1.4%), 566,439 ounces of silver (10.6 ounces per ton)(opt) and 3,120 ounces of gold (0.058 opt). In addition to the direct ship ore, a flotation mill operated on the property during the mid-1950s, and, although no production records exist for the mill, it is estimated that well over 20,000 tons were processed, based on the amount of tailings present.

Approximately 8,000 feet of underground workings were completed at South Mountain, most of it during the 1940s and 1950s. Two primary drift levels were developed, the Laxey Level (2000 feet long, 7145 feet amsl) and the Sonneman Level (2700 feet long, 6850 feet amsl). In addition to the two main tunnels, intermediate levels and stopes were mined. South Mountain Mines, Inc. conducted extensive exploration work in the late 1970s through the mid-1980s and expended well over three million dollars on the property. They extended the Sonneman Level approximately 1200 feet to intersect with the Texas ore zone and completed approximately 13,000 feet of underground and surface drilling. In the area of the Texas ore zone on the Sonneman Level, approximately 75 feet of high grade mineralization was intersected in by the drift where 19 chip channel samples collected by South Mountain Mines averaged 14.45% zinc, 3.98% lead, 0.17% copper, 8.17 opt silver and 0.21 opt gold.

A 43-101 compliant ore reserve has not been completed for the property. Drill spacing was not based on statistical parameters and assays were not analyzed utilizing 43-101 QA/QC standards. By the mid-1980s, South Mountain Mining felt they completed sufficient exploration to calculate in-house ore resources utilizing historic data, underground drilling, surface drilling, and underground channel sampling. They also incorporated resource calculations completed by the Defense Minerals Exploration Administration (DMEA) from the 1950s into their resources. South Mountain Mines calculated a nearly 470,000 tons (utilizing ten cubic feet per ton) with grades averaging approximately 10.0% zinc, 1.40% lead, 1.0% copper, 7.6 opt silver and 0.05 opt gold. They also completed a preliminary feasibility study, including metallurgical test work done by Dawson Metallurgical Labs in Salt Lake City, Utah.

N35W view. See map above for section line in plan view.

Mineralization is open along strike and is open to depth. At least nine separate ore zones have been mined, with the Laxey ore shoot having been mined from the surface to over 800 feet down dip, or 300 feet below the Sonneman Level. The potential mineralization may be as high as two million tons when the known ore zones are projected to a depth of 300 feet below the Sonneman working level.