He earned a degree in political sciences from the University of Arizona, served as an officer in the United States Army in Okinawa, Japan, and later became an insurance and marketing executive.

A soft-spoken and affable man, Walker had been President Nixon's special assistant responsible for both domestic and international travel.

Walker advocated a policy of "stabilization", foreseeing that NPS funding and staffing would be inadequate for a continuing high influx of new parks and program responsibilities.

[2] The plan called for the reduction of central offices and the establishment of sixteen ecological-cultural-geographical based clusters of 10-225 park units in seven regions.

Of the sixteen 'eco-clusters' envisioned in the plan, only those clusters based on older regional offices, i.e., Boston (Mid-Atlantic), Seattle (Pacific Northwest), and Santa Fe (Southwest) exist.