There have been five sapphire bearing dikes identified on the subject property. However, the primary dike that is generally referred to as the Yogo dike, is the only structure that has been partially developed and mined on a historical basis. The Yogo dike has had production using both underground and surface mining for over 5 miles of horizontal distance. The four other unexplored dikes have been delineated by surface trenching and preliminary geophysical surveys, but as of this date no exploration has been undertaken. The two deepest known historical workings were a 250 ft. shaft sunk by the British Syndicate in the early 1900s and a 350 ft. shaft sunk at the American mine. The British shaft was utilized for production up until the mine closure in 1928. The depth of this shaft was reported to be 250 ft. and the mine developed and mined extensively on three levels. Mining was done east and west of the shaft for 1,500 ft.
An independent professional geologist stated that the primary Yogo dike has a horizontal length of 30,000 ft. and under the assumption the dike extended to a depth of only 1,000 ft. and had an average width of 6 ft. using a factor of 80% removal and retention of 20% for underground support, the Yogo dike would potentially have 9,000,000 tons of material that could be mined and processed. Yogold will undertake a 12 hole drill program to verify not only the depth of the Yogo dike, but the width of the structure. In some of the historical reports, it was stated that the Yogo dike had widths of up to 30 ft. There are several examples of the Yogo dike being much wider than the 6 ft. used in the calculation of the potential Inferred Resource. At the rate of 500 tons per day or production of 175,000 tons per year, the inferred resource down to the 1,000 ft. level would have an estimated life of 50 years.