In 1911 a pair of men from Lovelock discovered the cave's vast guano deposits, and spent a year digging it out and shipping it to a buyer in San Francisco. From the beginning their work was impeded by the density of artifacts mixed throughout the guano. Most of it they discarded into a rubbish heap outside the cave. In 1912 the work proved to be no longer worthwhile, when a meter or two down, the proportion of ancient artifacts exceeded the proportion of guano. They contacted the University of California and told them the cave was theirs to take over if they wanted, and the department head sent anthropologist Llewellyn L. Loud to check it out. The Humboldt Sink was well known for its open archaeological sites pertaining to the Lovelock Culture, but this was a previously unknown location.
And it turned out to be the greatest yet. Nobody in the fields of anthropology or archaeology has ever received a greater bounty than Loud did on that day. To the amazement of the scientific community, he collected over 10,000 artifacts from the rubbish heap and various regions of the cave, mostly along the walls where the miners had not cut. Loud's workload was such that it took him 17 years before he was finally able to publish a comprehensive account of his findings.
In none of it did he report anything pertaining to giants.
In 1924 Loud and M. R. Harringon, with a number of Paiute assistants, continued the exploration. Again, no giants were mentioned.
Further expeditions in 1936, by N. Nelson and Heizer and Krieger collected relics, but no giants.
Krieger returned in 1949, 1950, and 1965. Still no giants.
https://skeptoid.com/episodes/4390