But now our National Parks are reforming man. The wildest of animals quickly become half-tame in any place that is safe. During the past few years thousands of excellent photographs have been made of big game in National Parks. Elk, antelopes, and mountain sheep have been photographed singly and in groups at the distance of only a few yards. "It is better to let the wild beast run And let the wild bird fly; Each harbors best in his native nest, Even as you and I." None of the big animals in the United States are ferocious. In parks it is men, not animals, who are on their good behavior--his hand restrained, man temporarily becomes as inoffensive as the animals. It may be, if we quit shooting animals on one side of a Park boundary-line, that in due time we shall become sufficiently civilized to stop killing people on the other side of a national boundary-line. That the habitual wildness of birds and animals is the result of experience, rather than instinct, was forcefully illustrated to me by a surprise that I enjoyed with wild mountain sheep in a side cañon of the Colorado River in Arizona. Bighorn sheep are proverbially alert and wild. Imagine my astonishment when two or three of a flock of bighorns walked up and touched me with their noses! Evidently they had never before seen man. Trustfully they approached to satisfy their native curiosity. For a number of days I was close to this flock, and several times I walked among them. They showed no excitement; they had nothing to fear. Without doubt, they had not been fired upon, chased, or even approached by man before. When I started for other scenes, one of the ewes of this wild herd followed me for more than an hour. Here were wild animals in a truly natural state! The abundance of easily watched bird and animal life in these numerous Parks affords a splendid opportunity to learn how these so-called wild people live and who they are. Our greatest animal is the grizzly bear. In the Parks we may make his acquaintance. The story of "Ben Franklin," who was reared by James Capen Adams, "Grizzly Adams," an early mountaineer and hunter of California, tells of a noble grizzly bear. While hunting in the Yosemite in 1854, Adams killed a mother grizzly and captured two tiny cubs. A greyhound suckled them, and Adams kept one of the cubs--Ben Franklin. Ben was never chained, but followed his master everywhere through the mountains with a devotion equal to that of a faithful dog. Adams always treated him with kindness and understanding, and trained him to carry huge packs. Ben also rendered other startling services.