Western Slope accounts for 68 percent of Colorado's 7,770 highway animal deaths

Over 7,770 animals died on Colorado highways in 2025. The vast majority of those carcasses were found on the Western Slope.

That is the headline number from the Colorado Department of Transportation, and it tells you where the danger lies if you drive a truck between Grand Junction and the Wyoming border. The state’s southwest region alone accounted for 39 percent of all reported collisions. The northwest region, which covers most of the western half of the state from Moffat County down to the San Juans, reported 2,226 animals killed. That is 29 percent of the state’s total.

Here’s the thing though: these numbers are not a census. They are an estimate based on opportunistic reporting. CDOT relies on its own road maintenance crews to spot bodies on the pavement, but they also use a roadkill app and data from Colorado Parks and Wildlife. Because it depends on who is out there driving and reporting, the data is considered underreported. It has inequalities. You are more likely to see a deer hit on Highway 133 than a coyote hit on a remote stretch of U.S. 40 where fewer crews patrol.

Lindsay Martinez, CDOT’s wildlife specialist, wrote in a note announcing the data that the information is vital for reducing collisions. But she warned that the numbers should only be used to study the same stretches of road over time. They are not for deep statistical analysis. They are for getting a general idea of what is being struck and where.

And the where is specific. If you live in Delta County, you know the pain. The 10-mile stretch between Paonia and Hotchkiss on Highway 133 had the highest number of roadkill reports in the entire northwest region last year. It aligns with high-risk areas identified in a 2019 study by CDOT and CPW. That study wasn't just a guess; it was a targeted look at the same corridors. The pattern hasn't shifted much.

Interstate 70 is still a meat grinder. The 10-mile stretch through Glenwood Springs reported high volumes of incidents. So did the highway between Dowd Junction west of Vail and Silverthorne. These are the commutes locals take every day. You merge onto I-70 at dawn, you hit the traffic near the Glenwood Canyon, and you are praying the elk don't step out from the timber just as you pass the exit for Carbondale.

Highway 13 between Craig and the Wyoming border, stretching south toward Garfield County, also saw some of the highest reports. U.S. 40 from Ma... well, the source cuts off there, but the implication is clear. The corridor is busy. The wildlife is abundant. The collisions are frequent.

The total number of animals killed across the state rose slightly in 2025. There were 273 more animals noted than in 2024. It is a small increase, but it matters when you consider that 68 percent of all reports came from the western half of the state. The southwest region had the highest volume of reported roadkill in the state. The northwest followed closely behind.

This is not just about deer. It is about the ecosystem intersecting with asphalt. The data shows which highways are the most dangerous. It shows which stretches of road are the worst offenders. It doesn't tell you exactly why the numbers are up or down in every single county, but it points to the places where drivers need to slow down.

Picture this: a driver on Highway 133, just north of Paonia, braking hard to avoid a mule deer that stepped off the shoulder. That incident gets logged. It gets counted. It becomes part of the 7,770 total. It is a reminder that the road is shared. And as long as the reporting remains opportunistic, the numbers will always be a lower bound. But the trend is clear. The western half of the state is where the collisions happen. And they are happening more often than they did a year ago.