Established in 1974 by the Wyoming Legislature, the Permanent Wyoming Mineral Trust Fund (PWMTF) is that state's oldest and largest permanent fund, with assets of $4.2 billion as of June 30, 2009. It is funded by a portion of severance taxes on mineral revenues and occasional direct legislative appropriations, while income from the fund goes to the state general fund. The fund covers part of the costs of running the state, and also acts like an endowment for the state by conserving its wealth for future generations.

|||Wyoming is richly endowed with natural resources, making its economy dependent on resource prices and hence prone to boom and bust cycles. The PWMTF cushions the impact of these economic cycles, while ensuring future generations share in the wealth generated by these finite resources.