Leonard D. Harris, 57, a structural geologist with the U.S. Geological Survey for the past 32 years who worked in its oil and gas resources branch, died of kidney failure July 27 in Prince George's Doctor's Hospital. He lived in Laurel.

Mr. Harris helped direct studies of the growth of mountain ranges and its relationship to possible oil and gas reserves. He worked on structural studies of the Appalachian Mountain range and the Ouachita Mountains of Arkansas. He also worked on studies evaluating coal resources in eastern Kentucky.

For his work as a research geologist, he was given the Interior Department's Meritorious Service Award in 1981. He was a member of the American Association of Petroleum Geologists and the Society of Economic Paleontologists and Mineralogists.

Mr. Harris was a native of Kansas City, Mo., and earned a bachelor's degree in geology at the University of Missouri. He served with the Marine Corps in the Pacific during World War II.

His marriage to Margaret L. Harris ended in divorce.

Survivors include his wife, Anita G. Harris of Laurel; three children by his first marriage, Douglas L., of New Jersey, Vickie L., of Alexandria, and Linda M. Boatman of Tennessee; a brother, Norman L., of Idaho, and two grandchildren