Proved reserves in the Gulf of Mexico Outer Continental Shelf (OCS) as of December 31, 2001, are estimated to be 16.51 billion barrels of oil and 172.0 trillion cubic feet of gas from 1,086 proved fields. Included in this number are 164 proved expired depleted fields; not included are the 57 unproved active fields. Estimates were derived for individual reservoirs from geologic mapping and reserve evaluation. Cumulative production from the proved fields accounts for 12.48 billion barrels of oil and 147.7 trillion cubic feet of gas. Remaining proved reserves are estimated to be 4.03 billion barrels of oil* and 24.3 trillion cubic feet of gas. These reserves are recoverable from 922 proved active fields.