This is an unpublished "white paper" that proposes standards for protecting habitat for grizzly bears in the Greater Yellowstone Ecosystem. This document contains a wealth of information that is too dense to summarize here, but here are a few excerpts from Section I:

"This paper is organized into four sections. The first constitutes a review and summary of literature pertaining to the responses of grizzly bears to humans. The second provides a rationale and parameters for what I call "micro-scale" security areas - areas that are functional at the scale of individual foraging bouts. The third section provides methods for calculating standardized road densities in a way that reflects access by motorized vehicles and the presence of cover. The fourth and last section provides a rationale and parameters for grizzly bear road standards in the Yellowstone area and, in addition, sets forth a conceptual frame-work for relating Yellowstone-specific standards to the global situation."

"Grizzly bears consistently under-use habitat within 100-500(914)m of roads. This under-use does not vary substantially with use levels or whether the road is paved or unpaved, and is exhibited at very low levels of traffic (0.5-1.9 vehicles/hr)(Aune and Kasworm 1989 [other cites follow]). Similarly, grizzlies under-use habitat where open road densities exceed 1 mile/mile2 (Mace and Manley 1993), and observations of bear sign are negatively correlated with km of road (Elgmork 1978)."

"Grizzly bears substantially under-use habitat near town-sites and major recreational developments in the Yellowstone ecosystem. This under-use extends out to between 4-5 km, and impairs daytime use by between 46-94% within this zone, depending on the season, food, and development (Mattson et al. 1987, Mattson and Knight 1992, Reinhart and Mattson 1990)."