He gained acclaim from architecture press and the American Institute of Architects for a number of house designs.

[2][3][4] After graduating, Bumgardner moved to Seattle, where he briefly worked for the Army Corps of Engineers before he was hired as a draftsman and specifications writer for architect Ralph Burkhard.

[2] His practice initially worked out of a home office at his residence on East Broadway, where he was joined in 1957 by two employees, both graduates from the University of Washington.

In 1958, he was hired as an architectural advisor for the Pacific Architect & Builder periodical, accompanied by a showcase of the Graham House.

[5] This design was widely publicized into architectural press, and resulted in a number of higher-profile commissions for his firm, especially with educational institutions.

[5] He designed the student residence halls and Seminar Building of the Evergreen State College in 1971–1972, the Port Ludlow Beach Club in 1972, and the South Campus Center of the University of Washington in 1974.