Just as I climbed above the last trees on the eastern slope of the Continental Divide, I saw a grizzly ambling along the other side of a narrow cañon, boldly outlined against the sky-line. I was so near that with my field-glasses I recognized him as "Old Timberline," a bear with two right front toes missing. He was a silver-tip,--a nearly white old bear. For three days I followed Old Timberline through his home territory and camped on his trail at night. I had with me hatchet, kodak, field-glasses, and a package of food, but no gun. The grizzly had disappeared by the time I crossed the cañon, but a clear line of tracks led westward. I followed them over the Divide and down into the woods on the other side. In a scattered tree-growth the tracks turned abruptly to the right, then led back eastward, close to the first line of tracks, as though Old Timberline had turned to meet any one who might be following him. The most impressive thing I had early learned in trailing and studying the grizzly was that a wounded bear if trailed and harassed will sometimes conceal himself and lie in an ambush in wait for his pursuer. I never took a chance of walking into such danger. Whenever the trail passed a log, bowlder, or bushes that might conceal a bear, I turned aside and scouted the ambush for a side view before advancing further. Old Timberline's tracks showed that he had now and then risen on hind feet, listened, and turned to look back. He acted as though he knew I was following him, but this he had not yet discovered. All grizzlies are scouts of the first order; they are ever on guard. When at rest their senses do continuous sentinel duty, and when traveling they act exactly as though they believed some man was in pursuit. Following along the trail and wondering what turn the grizzly would make next, I found where he had climbed upon a ledge in the edge of an opening, and had evidently stood for some seconds, looking and listening. From the ledge he had faced about and continued his course westward, heading for a spur on the summit of the Divide. We were in what is now the southern end of the Rocky Mountain National Park. The big bear and myself were on one of the high sky-lines of the earth. We traversed a territory ten thousand to twelve thousand feet above sea-level, much of it above the limits of tree growth. There were long stretches of moorland, an occasional peak towering above us, and ridges long and short thrusting east and west, and cañons of varying width and depth were to be seen below us from the summit heights.