Of the moneys received by the state from the federal government in accordance with Title 16, section 500, United States Code, fifty percent shall be spent by the counties on public schools or public roads, and fifty percent shall be spent by the counties on public schools as provided in RCW 28A.520.020
(2), or for any other purposes as now or hereafter authorized by federal law, in the counties in the United States forest reserve from which such moneys were received. Where the reserve is situated in more than one county, the state treasurer shall determine the proportional area of the counties therein. The state treasurer is authorized and required to obtain the necessary information to enable him or her to make that determination.
The state treasurer shall distribute to the counties, according to the determined proportional area, the money to be spent by the counties. The county legislative authority shall expend the fifty percent received by the county for the benefit of the public roads or public schools of the county, or for any other purposes as now or hereafter authorized by federal law.