Energy-producing states confront numerous challenges related to the boom-and-bust of resource extraction, including substantial fluctuation in revenue produced by severance taxes. Revenues surge as drilling expands during booms, creating many pressures for immediate expenditure. This often sets up enormous strain during bust periods when revenues plunge as longer-term needs emerge. This paper, however, examines the small set of states that have devised unique mechanisms to prepare for future busts. It reviews two periods (1970s and 2010s) in which six oil and gas-producing states amended their state constitutions to place severance tax revenues into permanent trust funds for long-term stewardship. It examines the key political factors that prompted the formation of these funds while also considering their resilience to date.