Cobalt, nickel, and manganese can be recovered quickly, cleanly, and selectively from cobalt-rich manganese ocean crust by leaching in dilute acid solutions in the presence of hydrogen peroxide. Common selective precipitation methods can then be used to recover these metals from the leach liquor. The leaching reaction produces only oxygen as a byproduct, and the waste residue from leaching was tested and found to be nonhazardous under existing Environmental Protection Agency specifications. The leaching process is effective in either fresh water or seawater. This research is a part of the U.S. Bureau of Mines program to identify the mineral resources of the exclusive economic zone and devise methods for recovering their valuable components.