Reserves against deposits.

A. A state bank shall maintain such reserves against deposits as may be required by the director or, if the state bank is a member of the federal reserve system, by the Federal Reserve Act or by the board of governors of the federal reserve system. B. The reserve fund shall consist of legal tender on hand on the premises of the state bank and money due on demand from a federal reserve bank or other bank approved as a reserve depository by the director, in such amount as the director may prescribe, but shall not exceed at any time the reserve requirement ratios promulgated by the board of governors of the federal reserve system for national banks. C. A state bank may invest up to fifty percent of the required cash reserves in direct obligations of the United States government, provided such are limited to not more than one hundred days maturity free from encumbrance or pledge.