The new I-25 Crystal Valley interchange will open in Douglas County, Colorado in 2027

Work is underway in Douglas County on the long-awaited Crystal Valley Interchange project. Construction began in March, but the idea was created in the 1980s.

Castle Rock officials say the interchange will provide a key regional transportation link for growing southern Douglas County. It will connect the east and west sides of Castle Rock and is expected to improve safety and mobility in the area.

In three short years, drivers on I-25 will see signs pointing to Exit 179, “Crystal Valley Parkway,” about two miles south of the Plum Creek Parkway exit.

“Honestly, I’m a little excited; I’m probably not the most popular opinion here,” said Crystal Valley Ranch resident Laurie Probsdorfer.

Although some neighbors have expressed concerns about the too-large investment, longtime Castle Rock resident Probsdorfer is looking forward to the connection via I-25 that the new transportation hub will provide.

“I’m so excited about Costco and all the things that come with it!” Probsdorfer said.

A Costco facility is expected to open in 2026 on the west side of I-25. It will be followed by the construction of thousands of houses as part of the “Dawson Trails” investment.

Thanks to the new junction, there will be room for new residents on the roads. Castle Rock says Plum Creek Parkway cannot handle the current traffic volume.

“Congestion on the Plum Creek Parkway is creating hazardous conditions, with traffic essentially backing up into lanes of I-25. This interchange will help alleviate congestion and provide greater safety for emergency vehicles,” said Aaron Monks, engineering manager for the City of Castle Rock Department of Public Works.

The $144 million construction project includes expanding the Crystal Valley Parkway bridge over I-25, building a new roundabout on Crystal Valley Parkway, a new bridge over the rail line and relocating portions of major roads.

“The existing eastern frontage must be moved east to make room for the abutment and on- and off-ramps to I-25. The western frontage also needs to be closed to make room for on- and off-ramps to southbound I-25,” Monks explained. “Then we need to build a road from the interchange down to Tomah Road on the west side of I-25 and a BNSF rail line to connect that route for southbound traffic to enter unincorporated Douglas County.”

While neighbors can expect construction delays in the meantime, including periodic overnight closures of the highway and frontage road, Castle Rock says in the long run it will reduce traffic and improve safety.

“We only have two entrances to our community and they are very well supported and the community continues to grow, so it will be great to ease the traffic and improve traffic flow a little bit,” Probsdorfer said.

The interchange should open in the summer of 2027. However, neighbors can expect changes to nearby roads to be completed sooner. The Crystal Valley Parkway roundabout is expected to open in November 2024. The new road, Dawson Trails Boulevard, is currently under construction in a separate project and should open next summer.

The Crystal Valley Interchange project is a partnership between the City of Castle Rock in Douglas County and the Colorado Department of Transportation. The city of Castle Rock says the entire project will cost approximately $143.5 million.

The funding breakdown is as follows:

· $53.6 million in developer contributions

· $24 million from Douglas County for the interchange and $11 million for West Frontage Road, which will eventually be known as Dawson Trails Boulevard

· An $8.5 million grant from the Denver Regional Council of Governments

· A $5.4 million BUILD grant from the U.S. Department of Transportation

· $1.7 million in city electricity credits

· $900,000 from BNSF Railroad

For more information about the project, click here.