Castle Rock’s Town Council on Tuesday unanimously approved a motion to lay the groundwork to sue Colorado’s most populous city over its immigration policies.

A councilmember said Castle Rock needs to address the crisis in Denver that he said is spilling over into neighboring counties and cities.

“I would like to direct (the) town attorney to begin conversations with Douglas County, the Douglas County attorney, and then also other municipalities around the Front Range that feel that they have been impacted negatively because of Denver’s failed migrant policy,” said Castle Rock Councilmember Max Brooks.

“I believe we should join together and sue Denver into stopping bringing in additional migrants,” the councilmember said.

Nearly 43,000 immigrants, many from Venezuela, have traveled to Denver after crossing America’s borders illegally. Plane, bus and train tickets purchased by Denver officials suggest about half have stayed in the region.

Early in the humanitarian crisis Denver officials decided that the city would assume the cost of temporarily housing and feeding immigrants.

Denver taxpayers have shouldered the majority of costs, with the latest tally at $74 million. Some have argued — including officials in El Paso, Texas — that the city’s policies, notably free shelter and paying for transportation costs to destination states, have served as a draw. The city has doubled down on those policies.

“They don’t have the services, they don’t have additional housing,” Brooks said, claiming that the influx of immigrants to Denver is the worst per capita in the nation.

Brooks was likely referring to news reports that, of the cities the Texas state government has bused immigrants to, Denver has received the most per capita.

“It’s spilling out into other communities,” Brooks said.

In mid-April, Douglas County filed a lawsuit against the state of Colorado over its “sanctuary” statutes they say restrict local law enforcement officials from working with federal authorities on illegal immigration. The county argued the laws are unconstitutional and preempted by federal laws.

Douglas and El Paso counties sue to overturn Colorado’s ‘sanctuary’ state laws

The lawsuit filed by El Paso and Douglas counties targets a 2023 law that restricts the ability of state and local governments from making agreements with federal immigration officials over the detention of immigrants who are unlawfully staying in the country, as well as a 2019 statute that blocks local law enforcers from arresting or detaining an immigrant solely on the basis of a federal immigration detainer.

Current Colorado laws also prevent state judicial officials from sharing information with federal immigration officials.

On Tuesday, Brooks said the town attorney should begin discussions over potential actions against Denver.

“Nobody outside of Denver asked to be part of it,” he said of the influx of immigrants. “If we were doing something here that negatively impacted Denver, you better believe we’d hear from them. It’s time that they hear from us.”

Councilmember Laura Cavey seconded Brooks’ motion, which drew unanimous support from the council.

Douglas County Commissioner George Teal, a former member on the Castle Rock council, expressed support for the potential litigation.

“We’re interested in joining Castle Rock, maybe taking the lead. This is what Commissioner Abe Laydon and I are discussing with the county attorney and joining them in that lawsuit against Denver,” he said.

The commissioner added: “It’s not just Castle Rock. It’s not just the county. We’re also talking to the municipalities.”

When asked for a response, a Denver mayor’s office spokesperson said the city won’t comment on any potential legal action.

“I don’t have a problem with someone coming inside the United States legally,” Castle Rock Mayor Jason Gray said.

“What I have a problem with,” he said, “(is) sometimes it appears the vetting system probably didn’t happen the way it should have up there. We need to protect our town and our county from potential mishaps. We want to be caring, and we want to make sure people coming in are doing so with the right way of doing it.”