Charles D. Gilfillan was for many years interested in the history of the great Sioux Outbreak in the Upper Minnesota valley. As attorney for many of the settlers that lost property by the Indians he recovered for them from the United States annuity fund large sums. His commissions for his work amounted to some $160,000. He and Major Return I. Holcombe, the Minnesota Valley historian, were friends since young manhood, and Mr. Gilfillan furnished the historian with desk room in his office. In 1898 the two men discussed the marking of historic sites in the Minnesota Valley, and Mr. Gilfillan declared that he would gladly spend $10,000 to identify and permanently mark such spots. Mr. Gilfillan then established the Minnesota Valley Historical Association, appointed its officers, and under its name, with himself as president and Return I. Holcombe as historian and agent, started to put his plans in operation. The historian got the necessary bill through the legislature, selected the sites, let the contracts, prepared the necessary historical material, issued booklets, and the like. A number of monuments and markers were erected, including the splendid Friendly Indian monument. Mr. Gilfillan's death in December, 1902, stopped the further work he had been contemplating. At the time of his death he had started plans for a monument costing $3,000 or more, a huge granite pyramid, to mark the actual battle ground of Birch Cooley.