Maricopa Point is the site of the Lost Orphan Mine, which continued operations into the 1960s. Daniel Hogan, a prospector and deputy sheriff who served under Theodore Roosevelt in the Spanish-American War, filed his copper claim in 1893.
He opened a tourist camp along the rim in 1936. For a while, the cabins and saloon were managed by Will Rogers Jr. Only after Hogan sold out did he learn that his mine contained some of the richest uranium ore in the Southwest, yielding millions of dollars of uranium for later owners and creating something of a nuisance for the National Park Service.
The parcel of land became part of the park in 1987. Access is restricted for safety reasons, but along the Rim Trail [1] you can see the headframe, shafts, cables, and other remnants of the mine, which bored deep into the earth.
Links:
[1] http://www.moon.com/destinations/grand-canyon/the-south-rim/recreation/hiking/rim-trail