Fauna Series No. 5

Fauna of the National Parks — No. 5 The Wolves of Mount McKinley

CHAPTER THREE:
DALL SHEEP (continued)

Distribution of Dall Sheep in the Park

The main ranges of Dall sheep in Mount McKinley National Park lie north of the backbone of the Alaska Range where the snowfall is much less than on the south slope. In an east-and-west direction, the sheep are found from the Nenana River to Mount Eielson, about 68 miles to the west. From Mount Eielson to the western boundary there are no sheep now except for some sporadic records. Scarcity of these animals west of Mount Eielson is apparently due to the absence of foothill ranges, there being too much snow on the short high spurs coming from the main range for much winter use. West of the park, hills occupied by sheep are again found in the Tonzana River region. Along the eastern border of the park, a few sheep occur between McKinley Park Station and Windy, near the Alaska Railroad. Eastward from the park boundary, sheep distribution continues on all suitable locations throughout the Alaska Range.

Because less range is used in winter than in summer, the winter and summer distribution will be discussed separately. (The areas of year-long use and purely summer use are marked on the map on page 7.)

Figure 19: Double Mountain and Teklanika River. This mountain is much used by sheep in summer, but is frequented very little by them in winter. Many caribou use the pass between the two peaks in crossing between Sanctuary and Teklanika Rivers. [May 17, 1939.]

WINTER DISTRIBUTION

In winter the sheep are found from the Nenana River to Mount Eielson, in suitable cliffs and slopes in the foothills and on the north end of a few of the spurs coming off the main range. From the Nenana River to Teklanika River sheep are largely confined to the long single "outside" or foothill ridge. The canyons through this ridge made by the Savage, Sanctuary, and Teklanika Rivers are especially suitable for winter range because of their ruggedness. Farther west, between Teklanika River and Stony River, the mountains available to sheep are a dozen miles in breadth. A depression a mile or more wide separates the "outside" range or foothills proper from the spur ridges coming off the main Alaska Range. At Savage River the tips of the spur ridges were formerly much used by sheep in winter, but this is no longer the case. Possibly the sheep had been too vulnerable to wolf attack there. At Toklat River the spur ridges which are separated from the foothills only by the gravel bars of the streams are still a part of the winter range.

The ridges on the winter range are mostly under 6,000 feet elevation and the sheep are usually found between 3,000 and 5,000 feet. When conditions are suitable they may range from a stream bed at 3,000 feet up the slope to 4,000 or 5,000 feet. At altitudes in excess of 5,000 feet food becomes scarce. As a rule there is relatively little snow on the winter range, even on the flats, although deep snows do occur occasionally. Prevailing south winds, which often become strong, blow many of the ridges and slopes free of snow. Although the prevailing winds are from the south, many north slopes also are blown bare. Much snow is blown into gullies and ravines and thus may at times impede free travel from one slope to another.

SUMMER DISTRIBUTION

When the winter snows melt sufficiently to permit freedom of travel the range of the sheep expands greatly. Many then move nearer the main Alaska Range, some going to the heads of glacial streams. In mid winter the snow is too deep in these regions to permit their use. Not all the sheep make these movements, for during the summer some sheep may be found over much of the winter range. Thus, on the winter range near East Fork, between 100 and 200 rams and some ewes may be found throughout the summer. Many of these rams have moved into the area from other parts of the winter range. There is apparently considerable movement by those sheep which summer on the winter range. Sheep are found all year in some numbers on Sable, Cathedral, and Igloo Mountains, and on winter range along the Toklat River as far north as the last canyon. The exclusive summer ranges are slightly higher in elevation.

Figure 20: Some of a large group of rams that spent the summer on the hills along East Fork River. This is also a winter range. [July 15, 1940.]

Continued >>>

Last Modified: Thurs, Dec 20 2001 10:00:00 pm PDT
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