WSPP Inc. (originally named Western Systems Power Pool) began with the November, 1983 distribution of a concept letter in which all members of the Western Electric Coordinating Council (WECC) were invited to join in the formation of a new electric power transaction "pool" with the purpose of testing to see if broader pricing flexibility for coordination and transmission services would promote increased efficiency, competition and coordination. Following an extended period of negotiation and development, the initial WSPP Agreement included 14 utility members across the western United States, including:

Arizona Electric Power Cooperative, Inc. Arizona Public Service Company Bonneville Power Administration Dept. of Water Resources of the State of California El Paso Electric Company Northern California Power Agency Pacific Gas & Electric Company Pacific Power & Light Company Portland General Electric Company Public Service Company of New Mexico Sacramento Municipal Utility District Salt River Project San Diego Gas & Electric Company Southern California Edison Company

The Agreement was filed with the Federal Energy Regulatory Commission (FERC) in November of 1986 by Pacific Gas and Electric Company of behalf of the charter members. In March of 1987, following FERC approval, WSPP began operations as a two year, multi-state, bulk power marketing experiment. Its initial purpose was to allow sales of power for short-term transactions to take place with maximum flexibility and minimal regulatory filings, and to test market efficiency and competition. In April of 1989, FERC allowed for a one year extension of the WSPP experiment to allow for additional data collection. At the end of that extension, an independent consultant was hired to review the collected data and assess the benefits of the experiment. FERC approved continuation of the WSPP experimental phase following the initial one year extension and while the collected data was analyzed, then, in April, 1991 FERC approved the WSPP Agreement on a permanent basis.

In 2005, the Western Systems Power Pool changed its name to better reflect its expanding footprint and the ever-evolving structure of the electric utility industry. No longer just a "Western" entity, devoid of any physical "System" and not performing in a traditional "Power Pool" manner (focused on market functions as opposed to system security functions), the organization became simply: WSPP, Inc.

The WSPP has proved to be extremely popular and beneficial to its members. The WSPP has grown from it's original 14 member foundation to over 350 current members with more being added each year.