Cars and driving - Mountains

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

The main route into Summit County follows the I-70 mountain corridor through the Eisenhower-Johnson Memorial Tunnel, and winter storms can bring traction laws, delays, or closures.

Published June 10, 2026 - Last verified June 15, 2026

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.

Filed under: Cars and driving Summit County

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Sources and review

Where this information comes from

This note uses official or primary sources where practical. Local details can change, so confirm before acting.

Last reviewed: June 15, 2026