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At this time, about the only information available on wolves was anecdotal and hearsay. Historical notes by Young and Goldman (1944) and Murie's (1944) field study on Mt. McKinley wolves were practically the only available published information. A few more studies followed. After the considerable publicity produced by Durward Allen's seminal investigation of the wolves and moose of Isle Royale National Park, published in National Geographic (Allen & Mech 1963), wolf studies proliferated. In 1967, the first wolf symposium was held by the American Society of Zoologists, culminating in the publication of the proceedings in the May 1967 issue of American Zoologist. By then the full force of the environmental movement could be felt. Private wolf organizations sprang up in many areas, and the wolf quickly gained a popular constituency in the U.S. and abroad.

In Italy, Luigi Boitani and Eric Zimen pioneered a study of the wolf in the Abruzzo Mountains east of Rome (Zimen 1981; Boitani 1986). The World Wildlife Fund and the International Union for the Conservation of Nature and Natural Resources (IUCN), now the World Conservation Union, took great interest in the wolf, and the animal was listed in IUCN's Red Data Book of endangered species. The IUCN Wolf Specialist Group was formed in 1973 (Pimlott 1975).

Meanwhile, radiotracking was developed in the early 1960s (Cochran & Lord 1963), a technique especially valuable to wolf research. Wolves were difficult to study with traditional methods because they were restricted to wilderness areas, highly elusive, and low in population density. Kolenosky and Johnston (1967) first radio-tracked wolves in Ontario. Mech and Frenzel (1971) then combined that technique with aerial tracking and observation, and numerous studies using these techniques followed.

The second U. S. Endangered Species Act was passed in 1973 and protected the wolf in the contiguous 48 United States beginning in August 1974. Recovery teams were appointed by the U. S. Fish and Wildlife Service for three wolf subspecies, the eastern timber wolf, the northern Rocky Mountain wolf, and the Mexican wolf, as well as the red wolf (U.S. Fish and Wildlife Service 1975, 1982a,1982b, 1987). At first many wolves were killed illegally (Mech 1977), but eventually that number dropped (Fuller 1989), and wolf reservoir populations in less accessible areas expanded (Fuller et al. 1992). They first recolonized the more remote areas surrounding their wilderness habitat, reinforcing the view that they were creatures of the wilderness.

Much of the public misinterpreted the wolf's endangered status in the 48 contiguous states, thinking it meant that no wolves were left anywhere else in the world. Private groups began to raise wolves to help restore populations, not realizing that Canada alone supported 50,000 of them. The wolf's apparent dependence on the wilderness was quantified in the 1970s and 1980s using road density as a measure. Roads were the routes by which the public and the government had been able to reach wolves to kill them. Thiel (1985) found that recolonizing wolves in Wisconsin lived only where the road density was less than 0.6 km/km², a figure corroborated for Michigan (Jensen et al. 1986) and Minnesota (Mech et al. 1988). The wolf then officially became a wilderness animal, and road densities became the yardstick by which wolf habitat suitability was measured by agencies and recovery teams.