Engelmann spruce is the largest tree in the park, and is usually found growing in moist places and near the lakes and streams. One needle, square in cross section, stiff and sharp; cones 2 to 3 inches long, scales papery. Blue spruce is not common and is found only in the Snake River bottoms. The form found here is not typical, lacking the blue cast. One needle, square in cross section, stiff and sharp; cones 3 to 5 inches long, scales papery. Creeping juniper is not common. It is a prostrate form, lacking definite trunk. Leaves awllike, one-half inch long or less, stiff and sharp, spreading from the twigs; fruit, berrylike. Aspen is the most common deciduous tree of the valley, growing on the slopes up to about 8,000 feet. The leaves are on very slender stalks and the slightest breeze puts them into motion, hence the popular names "Quaking asp" and "Quaking aspen." Leaves rounded, 1 to 3 inches broad, with a slender stalk of about the same length; bark smooth and whitish. Balsam poplar is found along some of the stream banks and is the largest deciduous tree of the park. Leaves about 3 inches long and 2 inches broad, longer than the stalk; bark smooth on the young trees, becoming rough as the trees get older. The small seed pods contain many seeds, to each of which is attached a tuft of white hair or "cotton"; hence one of the common names, "Cottonwood." NATURALIST SERVICE At Jenny Lake is located the park museum, which also serves as the ranger station. In it are housed exhibits pertaining to the history, geology, fauna, and flora of the Teton-Jackson Hole country. The collection devoted to mountaineering is in many respects unique. Adjacent to the museum is an open-air amphitheater where campfire talks on geology, wildlife, and other subjects related to the park are given every evening at dusk by a ranger-naturalist. A nature walk, auto caravan, or all-day hike is conducted each day by a member of the ranger-naturalist staff. [Illustration: THE TETON RANGE MIRRORED IN JACKSON LAKE _Copyright, Crandall._] An information desk is maintained at the museum, and rangers are there at all hours of the day to answer inquiries. Information service is also maintained at park headquarters. FISHING Grand Teton Park offers splendid opportunities for fishing. Fish may be taken with the artificial fly during most of the summer, but the lake or mackinaw trout which are present in Jackson and Jenny Lakes must be lured with bait and caught with heavy tackle by means of trolling. Other species of trout in park waters are the cutthroat (also known as native, red-throat, and blackspotted) and the brook or speckled trout. The park waters are being stocked through the cooperation of the United States Bureau of Fisheries. A Wyoming fishing license, costing $1.50 for State residents and $3 for nonresidents, is required. For $1.50, however, nonresidents may secure a 5-day fishing permit. SWIMMING