This project has been completed and the underpass is now open.
Boulder County’s Four Mile Creek Path project created a continuous, safe path along SH 119 between Boulder, Gunbarrel, Niwot and Longmont. See the project area map below.
The first segment connected the eastern terminus of the City of Boulder’s Four Mile Creek Greenway multiuse path with the northbound lanes of SH 119.
The second segment created an underpass below the BNSF railroad tracks connecting the Four Mile Creek Bikeway to the Cottonwood Trail.
The project was funded by a combination of a Federal Transportation Enhancement Grant obtained in 2007 and a dedicated fund for trail implementation passed by Boulder County voters in 2001 which was extended by voters in 2007 and 2024.
Four Mile Creek Trail Underpass Project Area