On his 1998 tax returns under “supplemental income,” Vice President Al Gore lists a $20,000 royalty payment from Union Zinc Inc. for the right to mine zinc from his 88-acre farm here in the verdant hills of the Cumberland River valley. In the 25 years he has held the zinc lease, Mr. Gore has earned more than $450,000. 

On his most recent tax return, as he has the past 25 years, Vice President Al Gore lists a $20,000 mining royalty for the extraction of zinc from beneath his farm here in the bucolic hills of the Cumberland River Valley. In total, Mr. Gore has earned $500,000 from zinc royalties. His late father, the senator, introduced him not only to the double-bladed ax but also to Armand Hammer, chairman of Occidental Petroleum Corp., which sold the zinc-rich land to the Gore family in 1973.