This study was conducted in the Superior National Forest (fig. 1) in northern St. Louis, Lake, and Cook Counties of northeastern Minnesota (92 deg. west longitude, 48 deg. north latitude), an area well described by Stenlund (1955). Most of the data were collected from within and immediately south of the Boundary Waters Canoe Area, a special wilderness region in which travel by motorized vehicles is restricted. The total study area encompasses approximately 1.5 million acres, and numerous lakes and rivers comprise about 15 percent of this area (fig. 2). The topography varies from large stretches of swamps to rocky ridges, with altitudes ranging from 1,000 to 2,300 feet above sea level (fig. 3). Winter temperatures lower than -30 deg. F. are not unusual, and snow depths generally range from 20 to 30 inches on the level. However, an important exception occurred in early 1969 when depths of 45 inches and more accumulated in much of the area. Further details on snow conditions in the study area during the period of this investigation are given by Mech _et al._ (see page 51). Conifers predominate in the forest overstory, with the following species present: jack pine (_Pinus banksiana_ Lamb.), white pine (_P. strobus_ L.), red pine (_P. resinosa_ Ait.), black spruce (_Picea_ mariana (Mill.) B.S.P.), white spruce (_P. glauca_ (Moench) Voss), balsam fir (_Abies balsamea_ (L.) Mill.), white cedar (_Thuja occidentalis_ L.), and tamarack (_Larix laricina_ (DuRoi) K. Koch). However, as a result of extensive cutting and fires much of the conifer cover is interspersed with large stands of white birch (_Betula papyrifera_ Marsh.) and aspen (_Populus tremuloides_ Michx.). Detailed descriptions of the forest vegetation were presented by Ohmann and Ream (1969). [Illustration: _Figure 1 (left half)--Map of the study area._] [Illustration: _Figure 1 (right half)--Map of the study area._ BOUNDARY WATERS CANOE AREA SUPERIOR NATIONAL FOREST] [Illustration: _Figure 2.--Lakes are common throughout most of the study area. (Photo courtesy of L. D. Mech.)_] [Illustration: _Figure 3.--Ridges, islands, swamps, and bays are part of the variable topography in the Superior National Forest. (Photo courtesy of L. D. Mech.)_] METHODS The observations discussed in this paper were all made from aircraft, the method of flying being that reported by Burkholder (1959) and Mech (1966a). The following aircraft were used (in order of size): Aeronca Champ,[1] Supercub, Cessna 172, Cessna 180, and Cessna 206. The smaller aircraft were excellent for holding in tight circles during observations but had the disadvantage of being slow and cold; the larger planes could cover the study area much more quickly and were more comfortable, but were not as maneuverable during observations. For radiotracking, to be discussed below, the best compromise seemed to be a Cessna 172.