In Patrick Geary's essential work, Councils of the BSA, he explains how the BSA utilized several different organizational structures for councils, "1913, the United States was divided into 3 districts. Western in San Francisco, Midwestern in Chicago, and Eastern in New York. In 1914, they became 6 districts." (ii)
Tim Brown, in his history of the Bluegrass Council, describes how the state of Kentucky was assigned to the "Midwest District", while the "Southern District... covered 14 states of the south and southwest."
Geary continues, "1918, a proposal was published to divide the United States into 13 Districts and place a National Field Scout Commissioner in charge of each. In 1919, only six Districts called Field Districts appeared in the 10th Annual Report. A National Field Scout Executive and a Deputy was in charge of each. Towards the end of 1919, another plan was created to increase efficiency. It consisted of 12 districts matching the 12 Federal Reserve Systems bank districts. All 12 were operating by the end of 1920. In 1921, these 12 districts were re-designated 'Regions'." (ii)
However, if you compare the boundaries of the Twelve Regions with those of the Federal Reserve banking system, these boundaries only loosely resemble each other.
Prior to the Order of the Arrow's integration into the BSA program in 1948, lodges were instead organized into a separate system of 26 areas. As part of the BSA, lodges were assigned to their respective region, with some regions further subdivided into areas, in which lodges participated in annual training conferences.
The Twelve Regions were in operation from 1948-1972. The 1973 New Section Operation created six regions: Northeast, East Central, North Central, Southeast.
Brown, Tim. "Blue Grass Council Complete History." Bluegrass Council, BSA, 2017. PDF file.
Geary, Patrick. Councils of the BSA, 6th ed. n.p., 2000, p. ii. Print.
Ghizoni, Sandra Kollen. "Reserve Bank Organization Committee Announces Selection of Reserve Bank Cities and District Boundaries." Federal Reserve History. Federal Reserve Bank of Richmond, 23 Nov. 2013. Web. 19 June 2016.
"Map of Local Councils-Boy Scouts of America." Rural Scouting Service, 1957. Rpt. in Order of the Arrow Conclave Handbook. By Frank Dingwerth and Chris Jensen. vol. 1, n.p., 1993, p. 1-5. Print.
Order of the Arrow National Committee. Area, Area Leaders, and Lodges. Boy Scouts of America, 1949. Print.