Claim: Night of the Grizzlies, written by Jack Olsen and published on June 1, 1969, documented the attack of two campers by grizzly bears, who are considered more aggressive compared to black bears.
Evidence: Jack Olsen June 1, 1969 Night of the Grizzlies (1969) is a book by Jack Olsen which details events surrounding the night of August 13, 1967, when two young women were separately attacked and killed in Glacier National Park, Montana, by grizzly bears. Grizzlies are considered more aggressive compared to black bears when defending themselves and their offspring. Helgeson was camping with her boyfriend Roy Ducat approximately ⁄4 mile (0.40 km) away from the Chalet; both Helgeson and Ducat were employed by the Glacier Park Lodge. The second attack was reported around 4 AM at Trout Lake; Koons had gone camping there with four friends, and all five worked at the Lake McDonald Lodge.