In 1945, Canalino Lodge 90 invited all the lodges in Area U to a Fellowship Conference to be held in Santa Barbara during the Easter holidays. A. R. (Andy) Groenink, Scout Executive of Mission Council Canalino Lodge 90, became the first Area Leader (the title for Region Adviser at the time). Ernie Houston, the Chief of SPE-LE-YAI Lodge 249, Verdugo Hills Council, Glendale, was elected the first Area Chief. There was no Lay Adviser the first year. Area U consisted of all Lodges in Arizona, California, Nevada, and the Canal Zone. Lodges represented were 90, 102, 207, 225, 249, 252, 278, 282, and 304. The total attendance was 68. Member Lodges not represented were 98, 127, 177, 228, 262, 263, 291, 298, 303 and 312. There were a number of adjustments in membership in these early years. Section A under Area U was formed in 1946. At this time Wynn Fairchild of 228 became the Lay Adviser and Carl N. Helmick of 127 became the Professional Adviser. Andy Groenink of 90 continued for a number of years as Region Adviser. In 1951 the Area U designation was eliminated and the Area we know today became Area XIIA.

Soon Area XIIA became too large and unwieldy and in 1955 it was divided into five Areas. The eight lodges of Orange, Riverside, San Bernardino, Imperial, and San Diego Counties remained in Area XIIA. These lodges were Navajo 98, Tahquitz 127 (later renamed Cahuilla), San Gorgonio 298, Atsa 380, Ahwahnee 430, Ashie 436, and Wisumahi 478. The Arizona lodges including Papago 494, Wipila Wiki 432, and Pang 532, were put in Area XIIF (known as Area 7 for about 5 years). By 1961, Area XIIF also included Victorio 177, Nebagamon 312, Chee Dodge 503 and Na Ko Na 551. This was the maximum number of lodges. Na Ko Na became inactive in 1962, but was reactivated as Salado 551 Lodge in 1965. Victorio merged with Papago in 1964 and Pang Lodge moved into Section W4B in 1973. The lodges in San Luis Obispo, Santa Barbara, Ventura, and Los Angeles were put in Area XIIE. These lodges were Tamet 225, Walika 228, Spe Le Yai 249, Siwinis 252, Topa Topa 291, and Ta Tanka 488. Conferences were held at council camps, military bases, colleges and high schools.

In 1972 the twelve regions were combined to form the six regions we know today. In the new terminology, an “Area” became much larger, and was sub-divided into “Sections” which corresponded to the old areas. Area XIIA became Section W4B whose Indian name is Machquigen meaning Many Bears, Area XIIE became Section W4A whose Indian name is Pethak’ Aluns meaning Thunderbird, and Area XIIF became Section W4C whose Indian name is Sinagua meaning Horned Lizard. Area 4 became known as the Sunshine Area.

In 1979, Section W4C became Section W5A when Area 5 was formed. This continued until 1988 when Area 5 was brought back as part of Area 4 and the designation Section W4C was again used.

In 1983 Sections W4A and W4B came together for an Area 4 Conference at Birmingham High School in Van Nuys, Ca. with over 1000 in attendance. In 1990, the Area had an Area Conclave to recognize the 75th Anniversary of the Order of the Arrow. This Conclave included Sections W4A, W4B, and W4C. Attendance was 1628

Other major changes are taking place as a result of Region reorganization and the merger of many of several councils in the Area.. As of January 1, 1993, Pang Lodge 532 and Ashie Lodge 436 merged to form Tiwahe Lodge 45. Also, Chee Dodge 503 was absorbed by Wipala Wiki Lodge 432. In July 1993, the National Order of the Arrow Committee released the new Field Operations Guide. As a result, the position of Area Adviser was eliminated. Also, the Area Director is now directly responsible for the position of Staff Adviser and may in fact fill the position himself. In 1995, the position of Area Adviser was put back in the program as optional. As of January 1996, Chumash 304 and Canalino 90 lodges merged to form Chumash Lodge 90. The Service Lodge, Yowlumne 303, for the 2002 W4A Conclave will move to Section W3B effective at the end of the Conclave.