The Lost Cement Mine is a legendary gold vein situated in the eastern Sierra Nevada of California, United States.

They traveled near the headwaters of the Owens River, and found some hardened red igneous rock that may have had a large amount of gold in it.

In miner's parlance of the era, the red igneous rock was known as "cement", hence the name of the lost mine.

[1] Doctor Randall and his assistant Gid Whiteman spent years looking for the ore in the pumice hills to the south and west of Deadman Summit.

Mark Twain was near Mono Lake and joined in the search, which was documented in his book Roughing It.