The protective coloring of the animal makes it difficult to distinguish among the rocks, and it is commonly heard before it is seen. The sharp, short bleat, almost a chirp or squeak, often repeated at rapid intervals when the pika is alarmed, is distinctive. If the observer remains motionless, and carefully searches nearby with his eyes, he is almost certain to see a tiny “rock-rabbit” scamper quickly and with silent, sure feet across the rocks, to disappear in a crevice or to perch on an exposed boulder. Should the watcher remain quiet, the pika will resume its interrupted activities until again disturbed. [Illustration: The busy beaver is an industrious engineer.] The well-chosen shelter of the pika, deep down beneath the rocks, affords adequate protection from most predators. Only the weasels, and their relatives, the martens, are capable of following these elusive creatures through the talus. Undoubtedly the hawks and eagles may strike suddenly from the air and be successful in capturing a pika less alert than his fellows, but such occasions must be rare. PACIFIC BEAVER _Castor canadensis leucodonta_ Gray The beaver is the largest North American rodent, and the species found in Mount Rainier National Park is the largest of any of the recognized geographical range. An adult will weigh thirty pounds or more, up to a maximum of sixty pounds. The form is robust; the tail is broad, flat, and scaly; the ears are short; the hind feet webbed. The pelage is composed of short, soft underfur, with long guard hairs. The sexes are alike in size and color, a dark, glossy, reddish brown above, lighter brown below. The beaver is aquatic in habit. _Specimens in park collection:_ Mounted specimen, Longmire Museum, Park Headquarters. The geographical range of the beaver extends over most of North America from the Rio Grande northward. Beaver are not now abundant in the park, and it is doubtful that they were ever numerous. Observations have been made in many sections, notably Fish Creek, Tahoma Creek, along the Nisqually River from the park entrance to the mouth of the Paradise River, Longmire Meadows, the Ohanapecosh River, and Reflection and Tipsoo Lakes. Records indicate that Fish Creek and Tahoma Creek are the sites most extensively used by beavers during recent years, although intermittent activities have been noted in the vicinity of Longmire Meadows. A colony on Kautz Creek was undoubtedly destroyed by the flood of October, 1947.