Block tried to get the mining concession but was beaten to it by a Syrian named Kunkar, who worked the mine from 1923 to 1925.
Analysis of old mine plans shows that most of the workings were developed by Kunkar on the very steep slope--averaging 45[degrees] gradient and reaching 60[degrees] in places--below Falcon's Rock at the northwest end of a northwest-trending ridge.
Additions to the plans show that Block mined the interval between Socavones Calisaya and Kunkar between 1935 and July 1938, over a distance of about 40 meters, and made various drives and cross-cuts off these levels, with a maximum length of 20 meters.