Agency spokesman Matt Elliott says the 66-year-old Allbaugh announced during Wednesday's board meeting that he's resigning, effective immediately, from the post he's held since 2016.
Known for his Marine-style haircut and straight talk, Allbaugh took over a state prison system with aging, overcrowded facilities and increased scrutiny after a series of problematic executions.
Allbaugh announced in March 2018 the agency would begin developing a plan to execute inmates using nitrogen gas, but no details have been released.
Allbaugh was a longtime Republican political operative in Oklahoma who headed up George W. Bush's gubernatorial campaign in Texas in 1994. He also managed Bush's presidential campaign in 2000 before being appointed head of the Federal Emergency Management Agency.
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