Born and raised in Kent, James Mathias Klontz spent much of his early years working with his father and five brothers at the family cabinet shop (Auburn Cabinet Works). After graduating from high school in 1937, Klontz worked full time at the cabinet shop to earn enough money to attend college. He received his formal architectural training at the University of Washington, graduating in 1943. Upon graduation he enlisted in the Army, and rose to the rank of Corporal during World War II.

After the war, he returned to Seattle and began his architectural career with the firm of Bliss & Massar. With experience in hand in 1951, he opened his own independent practice.  With too many projects to handle on his own he took on a partner, George E. Wrede in 1956.

Under the name Klontz & Wrede, the firm focused primarily on religious facilities and educational projects and became a favorite of the Catholic Archdiocese of Seattle, obtaining numerous commissions for church and parochial schools. Known work includes an addition to the Bellevue Methodist Church (1956); Our Lady of Fatima Church (1952, 1968) in Seattle’s Magnolia neighborhood; a convent for St. Benedict’s Catholic Church in Seattle’s Wallingford neighborhood; St. Patrick’s Parish in Seattle (1961); and a large-scale facility for St. Monica’s Parish on Mercer Island (1960).

Secular works by Klontz & Wrede included a variety of shopping centers, clinics and office buildings. Among their most notable projects is the Alcoa Building (1963); a large PX Market in Bellevue (1961); a Thriftway Shopping Center in Inglewood (1965); and a Nordstrom Store in Bellevue (ca. 1962).

Klontz continued to practice with various associates until his retirement in 2008. At the time he was the second oldest practicing architect in the State. Klontz passed away in Seattle on November 16, 2010 at the age of 90.