Phillip L. Jones, 51, who taught history and geography at Montgomery Blair High School in Silver Spring for 22 years and who was a freelance writer, died of cancer yesterday at the Rockingham Memorial Hospital in Harrisonburg, Va.

Mr. Jones began his career at Montgomery Blair in 1955. He was born in Crete, Neb., and grew up there and in Bend, Ore. For several years he took students on summer trips to the West so they could see at first hand some of the places he taught about during the school year. He retired in 1977 for reasons of health.

As a writer, he wrote articles and television scripts as well as short stories and an autobiographical novel, "Searching for the Wind," which was published privately. An account he wrote of the Great Blizzard of 1888 appeared in The Washington Post in 1968. He wrote the scripts for three episodes of NBC-TV's "Explorer" series.

Last October, former students and colleagues gave a retirement dinner for Mr. Jones at which they announced formation of the Phillip L. Jones Scholarship Fund to be awarded to the student whose grade average improves the most from the time he or she enters Montgomery Blair and the time he or she graduates.

Mr. Jones served in the Army in the occupation of Japan after World War II. He graduated from the University of Oregon in 1952 and taught in Oregon before moving to the Washington area in 1954. For 11 years he commuted from his home in Hinton, Va., near Harrisonburg, to Silver Spring.

Survivors include his wife, Nancy, of the home; four children, Stephen, Randall, Lauren and Martin, also of the home; a stepdaughter, Rain Worthington, of New York City; his parents, Mr. and Mrs. John G. Jones, of Rockville, and a brother, Leland S. Jones, of Westwood, N.J.

The family suggests that expressions of sympathy be in the form of contributions to the Phillip L. Jones Scholarship Fund, c/o the Rockingham National Bank, Harrisonburg, Va.