Colorado’s birthday bridge has a bigger price tag than the $18-20 million first suggested.

Internal project documents obtained through an open records request by The Denver Gazette’s news partner 9NEWS show that the project, which includes plans to build a pedestrian walkway over Lincoln Street in front of the Capitol in honor of Colorado’s 150th birthday, will cost $28.5 million.

The price is “40 to 60% more than the state has been saying,” according to 9NEWS Next anchor Kyle Clark

“The records we obtained show that $18-20 million price tag that is being floated is just part of the cost of the bridge,” Clark said during his Tuesday broadcast. “The full project is far more expensive.”

Dubbed the CO150 Walkway, the winding structure will feature public artwork integrated throughout the pedestrian experience, highlighting the “diverse stories and values of Colorado.”

However, the project has been met with opposition from Historic Denver, the city’s leading historical society.

In a news release, Historic Denver expressed several concerns with the proposal, highlighting the walkway’s disturbance of the otherwise symmetrical Civic Center Historic District as well as its potential lack of use by pedestrians who will more likely continue to use street-level crossings at Colfax Avenue and 14th Avenue.

Funding for the project would come from a mixture of public and private dollars.

The state has already launched a CO150 Walkway website soliciting project sponsorships ranging from $10,000 to $1.5 million.

The Denver Gazette’s news partner 9NEWS.com and reporter Michael Braithwaite contributed to this story.