Colorado reported 35,302 collisions between animals and vehicles from 1986 through 2004. The actual number may be much higher, since the available records are sketchy — in 60 percent of the collisions, the species involved isn't even identified — and many minor accidents involving wildlife aren't recorded. The highest incidence of collisions resulting in human injury occur in the fall, when many large game animals are moving from summer to winter range. Drawing on available data, the Southern Rockies Ecosystem Project identified the following Colorado roads as "extremely hazardous" for motorists and wildlife:
I-70 — Floyd Hill/Mt. Vernon Canyon: One semi, sixteen dead elk, January 23, 2009.
U.S. 285 — Morrison: Busy interchange, for both cars and critters.
U.S. 160 — Durango to Bayfield: Seventy percent of all accidents due to wildlife.
U.S. 160 — Durango to Mancos: Yes, it's just as bad heading west as east.
U.S. 550 — Durango to Montrose: Heading north out of Durango isn't any better.
I-25 — Castle Rock to Larkspur: One of the last undeveloped stretches of the Front Range, hence one of the most dangerous.
State highways 82 and 133 — Glenwood Springs to Marble: A corridor for celebrities, large ungulates and other exotics.
State Highway 36 — Boulder to Lyons: Commuter central.
I-70 — Eagle: Scene of the Great Wapiti Wrangle of 2009.
Other roads to drive with care because of high rates of animal-vehicle collision: SH 119 to Blackhawk, SH 9 between Frisco and Breckenridge, U.S. 285 through Park County.