Every county in Colorado is effectively a sanctuary county because statewide laws, not local ordinances, set the rules. Under Colorado Revised Statutes Title 24, Article 76.6 and related legislation, no sheriff or police officer anywhere in the state may honor a civil ICE detainer, hold someone past their release date for immigration purposes, or contract with private immigration detention operators. A few places, most visibly Denver, Pitkin County, and the city of Boulder, have added their own resolutions on top. But the baseline applies in all 64 counties, whether the local sheriff supports it or not.
What “Sanctuary County” Means in Colorado
The word “sanctuary” gets used loosely, and in Colorado it can mislead you. Because state law preempts the field for the specific practices people associate with sanctuary policy, a sheriff in Weld County and a sheriff in Denver face the same statutory restrictions on detainers, release timing, information sharing, and detention contracts. The label typically gets attached to jurisdictions that have gone further with their own resolutions, executive orders, or ordinances.
The practical gap between a “sanctuary” county and a non-designated one in Colorado is smaller than the label suggests. A county that passed its own resolution may prohibit officers from asking about immigration status during any encounter, or require a judicial warrant before releasing any non-public information. Counties without a resolution still follow state law, which produces most of the same outcomes. Federal agents run into roughly the same operational walls either way.
The Three State Laws That Create the Baseline
HB 19-1124: No Honoring ICE Detainers
Signed in 2019, HB 19-1124 is the law most people mean when they call Colorado a sanctuary state. It bars any Colorado law enforcement officer from arresting or detaining someone based solely on a civil immigration detainer from ICE. Those detainers are administrative forms, not judicial warrants. Colorado treats holding someone past their release date on a detainer as a warrantless arrest, which the legislature declared unconstitutional based on prior Colorado Supreme Court precedent.1Justia. Colorado Code 24-76.6-102 – Civil Immigration Detainers – Legislative Declaration
The law doesn’t block all cooperation. Officers can still assist federal authorities who present a warrant signed by a federal judge or magistrate, and they can honor any writ from a state or federal judge ordering a prisoner transfer. They also remain free to investigate criminal activity jointly with federal agencies.1Justia. Colorado Code 24-76.6-102 – Civil Immigration Detainers – Legislative Declaration A judicial warrant based on probable cause still works. An ICE administrative form does not.
The same statute restricts probation officers from providing personal information about individuals to federal immigration authorities. If federal agents want to interview someone in custody, the person must first be told that the interview is being sought by immigration authorities, that they can decline and remain silent, that they can speak with an attorney first, and that anything they say could be used in immigration proceedings.2Colorado General Assembly. HB19-1124 Protect Colorado Residents From Federal Government Overreach
HB 23-1100: No Private Immigration Detention
Effective January 1, 2024, HB 23-1100 prohibits any state or local government entity from entering into agreements to detain individuals in privately operated immigration detention facilities. It also bars government entities from selling property for such facilities, paying costs related to building or running them, receiving payment for detaining people for civil immigration purposes, or offering financial incentives to private detention operators.3Colorado General Assembly. HB23-1100 Restrict Gov Involvement In Immigration Detention
Any existing immigration detention agreement had to be terminated by January 1, 2024, or as soon as contract terms allowed. Local governments can still provide health and safety resources to people detained for immigration purposes and can contract for health, utility, and sanitation services to detention facilities.3Colorado General Assembly. HB23-1100 Restrict Gov Involvement In Immigration Detention
SB 25-276: No Delaying Release for ICE
Passed in 2025, SB 25-276 explicitly prohibits jail custodians from delaying a defendant’s release for the purpose of an immigration enforcement operation.4Colorado General Assembly. SB25-276 Protect Civil Rights Immigration Status Where the 2019 law addressed detainers, this one closed a subtler gap: jail staff slow-walking release paperwork or timing an inmate’s release to line up with an ICE arrival.
Counties and Cities With Extra Local Protections
Denver
The City and County of Denver has the most developed local framework. Denver Executive Order No. 142 and Denver Ordinance No. 940-17 sit on top of state law. The city describes itself as a “welcoming city” and states that city employees do not enforce federal immigration laws, that police officers do not ask about immigration status during routine encounters, and that the city does not inquire about immigration status unless required by law.5City and County of Denver. Denver’s Federal Immigration Enforcement Response Denver’s policies were specifically named in a 2025 federal lawsuit challenging Colorado’s sanctuary framework.
Pitkin County
Pitkin County’s Board of County Commissioners passed a 2017 resolution affirming the county as a “welcoming community for immigrants.” County departments and personnel cannot perform the functions of a federal immigration officer or participate in the 287(g) program. The sheriff’s office cannot stop or arrest someone based solely on suspected immigration status or a civil immigration warrant. No county department can share non-public information such as release dates, home addresses, or work addresses with ICE or CBP without a judicial warrant. The resolution also bars the sheriff from delaying bail or release for immigration enforcement purposes.
Boulder
The city of Boulder passed a sanctuary city declaration. Boulder County commissioners have publicly stated the county complies with federal immigration law while pushing back against federal characterizations of the county as noncompliant. Boulder County was included on a federal list of sanctuary jurisdictions despite the county’s position that it follows the same state laws as every other Colorado county.
What Changes at the Jail
The jail is where sanctuary laws show up most visibly. When someone finishes their sentence, posts bond, or is otherwise eligible for release, jail staff must let them go on schedule. They cannot hold the person an extra hour to give federal agents time to arrive, even if ICE has filed a detainer request.1Justia. Colorado Code 24-76.6-102 – Civil Immigration Detainers – Legislative Declaration They also cannot slow-walk the release paperwork to accommodate an operation.4Colorado General Assembly. SB25-276 Protect Civil Rights Immigration Status
Facility staff are restricted from sharing non-public information with federal immigration authorities. An inmate’s release date, home address, or work address cannot be handed to ICE or CBP unless the information is available to the general public or the request is backed by a judicial warrant. If a federal agent wants to take custody of someone, they need a warrant signed by a judge. An administrative warrant signed by another ICE agent does not meet the Colorado standard.
Counties that violate these restrictions expose themselves to litigation for unlawful detention, which is the real enforcement mechanism behind the rules.
What Changes During a Police Stop
On the street, officers performing routine duties like traffic stops or investigating minor offenses are not supposed to ask about a person’s citizenship or immigration status for civil immigration enforcement purposes. This posture runs across departments. The Colorado Springs Police Department’s general order, for example, prohibits officers from requesting information or documents to determine immigration status unless required by state or federal law.6Colorado Springs Police Department. General Order 305 – Immigration and Foreign Nationals – Section: .10 Requesting or Collecting Information
Officers also cannot volunteer non-public personal information to federal immigration agents while doing their jobs. Someone’s workplace, daily schedule, or home address is off-limits absent proper legal authority. Officers who ignore these rules can face internal discipline, and departments can face liability under state civil rights provisions.
Sanctuary Laws Don’t Stop ICE From Operating
This is where readers most often get confused. Sanctuary laws limit local cooperation. They do not stop federal agents from conducting their own operations on their own authority. ICE agents can still arrest people in Colorado. They can conduct operations at apartment complexes, businesses, and public spaces. What they cannot do is use local police, local jails, or local government resources to help them.
In 2025, ICE conducted high-profile operations at apartment buildings in Aurora and Denver in early February and raided a Colorado Springs nightclub in April. Immigration attorneys reported that roughly 88% of people detained through their organizations in 2025 were picked up internally, at workplaces, homes, or during traffic stops, compared with less than 10% in 2024. The state framework pushes federal enforcement toward independent operations rather than jail pipelines. It does not create a shield.
The 287(g) program, which lets local agencies sign agreements delegating limited immigration enforcement authority to their officers, has surged across the Mountain West but remains effectively blocked for Colorado agencies. Officers cannot honor detainers, cannot share non-public information, and cannot delay releases, all of which are central to how 287(g) works. When a Teller County sheriff attempted such an agreement, it was stopped through legal action.7U.S. Immigration and Customs Enforcement. Delegation of Immigration Authority Section 287(g) Immigration and Nationality Act
The Federal Challenge and Funding Pressure
Colorado’s laws sit in tension with 8 U.S.C. § 1373, which says no state or local government entity may prohibit or restrict any official from sending, receiving, maintaining, or exchanging information about an individual’s citizenship or immigration status with federal immigration authorities.8Office of the Law Revision Counsel. 8 USC 1373 – Communication Between Government Agencies and the Immigration and Naturalization Service A companion provision, 8 U.S.C. § 1644, uses nearly identical language aimed at state and local entities.9Office of the Law Revision Counsel. 8 USC 1644 – Communication Between State and Local Government Agencies and Immigration and Naturalization Service
In 2025, the United States filed a lawsuit challenging HB 19-1124, HB 23-1100, SB 25-276, and Denver’s municipal laws, arguing they were preempted by federal immigration law. In March 2026, a federal district court dismissed all of the government’s claims, finding it had failed to state viable claims and that ruling otherwise would conflict with the Tenth Amendment. The federal government could appeal, and this area of law is actively contested.
Separately, federal funding is being used as leverage. A January 2025 executive order directed the Attorney General and the Secretary of Homeland Security to take lawful actions to ensure that sanctuary jurisdictions do not receive access to federal funds.10The White House. Protecting The American People Against Invasion An April 2025 order directed every federal agency head to identify grants and contracts to sanctuary jurisdictions for suspension or termination.11The White House. Protecting American Communities from Criminal Aliens The Department of Justice’s COPS Hiring Program requires applicants to certify compliance with 8 U.S.C. § 1373.12COPS Office. COPS Hiring Program The Byrne Justice Assistance Grant program has imposed conditions requiring release dates of incarcerated undocumented individuals and federal access to those individuals in custody, both of which Colorado law prohibits. Whether these funding conditions will actually be enforced against Colorado remains unresolved.