BISMARCK (AP) - North Dakota's oil tax "Legacy Fund" now has $535 million in assets.
In its 13 months of existence, the fund has collected more than a half-billion dollars.
North Dakota voters approved the fund in 2010.
It gets 30 percent of the state's oil tax collections. None of the money can be spent until 2017, and even then it takes a two-thirds vote of the Legislature to dip into it.
North Dakota Treasurer Kelly Schmidt says $45 million was deposited into the fund this month. It's been collecting oil tax revenue since September of 2011.
Schmidt says the fund has been growing much faster than anticipated because of rising North Dakota oil production and high prices.