June 30, 2017, is an important date for the state’s Legacy Fund. After that, earnings from the fund can be transferred to the state’s general fund. Earnings from prior to that are considered part of the principal and can only be spent by two-thirds majority vote in both houses of the legislature. The fund currently has about $3.7 billion; if left untouched, it is forecast to generate $120 million in revenue per biennium.