New I-25 interchange in Colorado to fully open this weekend at Crystal Valley in Castle Rock

I-25's newest exit will officially open this weekend. It's Exit 179, Crystal Valley, in Castle Rock.

In the last decade, the population in Douglas County has grown almost 24%. To keep up, Castle Rock is opening a new interchange off I-25 at Crystal Valley Parkway.

It will serve drivers in the Crystal Valley community and those soon to call the new Dawson Trails community home, plus plans for Costco, King Soopers, and HCA HealthONE have also been approved.

"We were the only one here at the beginning, but now we see the growth of this area," said Rippy Bhangu, owner of Crystal Valley Wine & Spirits.

Bhangu invested in the area early, buying land and building the Crystal Valley Commons retail complex more than six years ago.

"Since the construction started a couple of years ago, it changed the whole life of this neighborhood," Bhangu said.

The Crystal Valley neighborhood soon welcomed thousands of neighbors east of the highway. Major growth is brewing on the west side with the first homes in the Dawson Trails neighborhood and a Costco, set to open early next year.

"Costco will be huge for this city and town," said Humberto Tiscareno, owner of Fit Body Boot Camp in Crystal Valley Commons.

"We're really excited for Costco," said Nicole Muller, a Crystal Valley neighbor. "Right now, for groceries, we have to drive 15 to 20 minutes, and if we want to go to Costco, we have to drive 45 minutes, usually with traffic. So this is going to be a huge lifesaver."

Connecting it all is the Crystal Valley interchange, set to fully open this weekend.

"Originally planned in the '80s, it's been years in the making," said Ross Stanley, project manager for public works with the town of Castle Rock.

The $150 million project finished on budget and eight months ahead of schedule.

"It's our number one transportation project in Castle Rock, so it's a big deal for our residents to have a little transportation ease," said Jason Gray, Castle Rock mayor.

The southernmost connection for I-25 in Castle Rock, Gray says the interchange will provide a critical connection on the south end of town.

Earlier this year, the northbound on- and off-ramps opened up, alleviating traffic by 50% at the Plum Creek interchange.

"Already, with just the one part being open, it's like five to eight minutes faster to get to school," said Muller.

When the southbound on- and off-ramps open this weekend, the town says traffic will improve even more.

"Now with this new intersection, it will be so easy for people in the morning and evening. So we'll see the growth in our store too," Bhangu said.

It's a long-awaited relief to Crystal Valley neighbors who have relied on the Plum Creek exit and frontage road for years.

"The frontage road traffic has been sometimes just bumper to bumper," said Tiscareno. "It's just going to make everything easier."

"He goes to school in Larkspur, and so instead of 20 minutes to get him down there, it's going to take like 12 minutes, which is huge," said Muller of her young son.

Castle Rock says the entire project cost is about $144.7 million. The funding partners include:

• $53.6 million in developer contributions
• $24 million from Douglas County for the interchange, plus $11 million for the West Frontage Road, which will be known in the future as Dawson Trails Boulevard
• $8.9 million grant from the Denver Regional Council of Governments
• $5.4 million BUILD grant from the United States Department of Transportation
• $1.7 million in Town electric credits
• $900,000 from BNSF Railway