Mountains

Getting to Summit County in winter means planning for the I-70 mountain corridor

Cars and driving Summit County mountain driving i-70 traction law winter roads

Summit County looks close to Denver on a map. In winter, the map does not tell the whole story.

The main way in is the I-70 mountain corridor, which climbs through the high country and crosses under the Continental Divide at the Eisenhower-Johnson Memorial Tunnel. Storms can slow that drive, trigger traction or chain requirements, or close the road for a while during avalanche control or crashes. Some larger or hazardous loads are routed differently than ordinary cars. A drive that feels routine on a clear day can become a very different trip in a storm.

Why care: a new resident or visitor who assumes a quick, all-weather highway can get caught out. Planning around the forecast, carrying the right tires, and checking road status before leaving is normal mountain practice, not overcaution.

Before a winter drive to Summit County, check CDOT’s road-conditions site at cotrip.org for current conditions and any traction or chain requirements in effect.

Sources

Official or primary sources used for this note. Local details can change, so confirm before acting.

Reviewed: June 15, 2026 Colorado Dept. of Transportation COtrip

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