A right-of-way through, over and across any state lands not held under a contract of sale, is hereby granted to any railroad company organized under the laws of this state, or any state or territory of the United States, or under any act of congress of the United States, to any extent not exceeding fifty feet on either side of the center line of any railroad now constructed, or hereafter to be constructed, and for such greater width as is required for excavations, embankments, depots, station grounds, passing tracks or borrow pits, which extra width shall not in any case exceed two hundred feet on either side of said right-of-way.