The American Civil Liberties Union of Colorado is appealing a judge’s ruling that allows the Teller County sheriff to continue operating a program under which deputies can conduct federal immigration enforcement. Teller County Sheriff Jason Mikesell has been operating under a 287(g) agreement, a program state and local law enforcement agencies can enter into with the federal government, which trains and allows deputies to enforce federal immigration laws. In the Teller County jail, that means the deputies who go through the program can identify inmates as immigrants who are potentially violating civil immigration law and then hold them until Immigration and Customs Enforcement picks them up for immigration detention. But the ACLU contends that this goes beyond a county sheriff’s authority and is a violation of the Colorado Constitution — because inmates are held beyond their release date without a signed judge’s order — and a 2019 state law that limits cooperation between local law enforcement and ICE. In late February, a Teller County District Court judge sided with Teller County, saying the sheriff’s deputies are acting as “de facto federal officers” when performing those functions. The ACLU filed its notice to appeal with the Colorado Court of Appeals on Thursday, further extending the years-long legal case.