The legal battle over desegregating public schools in Cleveland, Miss., has dragged on for more than five decades. And it appears that it isn’t going to end anytime soon, with the school district this week saying that it will appeal a recent federal court order to desegregate its middle schools and high schools.

A federal judge told the small Mississippi Delta district this spring that it had not yet overcome its segregated past and ordered it to combine its two high schools — and its two middle schools — to finally achieve the “greatest degree of desegregation possible.” The decision, which came just days before the federal government released a report on the resurgence of segregation in the nation’s public schools, drew widespread attention.

The district immediately objected, arguing that its open-enrollment policy — which allows middle school and high school students to attend the school of their choice — had created a greater degree of integration in Cleveland than in many other school districts across the South.

And now the district’s school board has decided to formally challenge the court’s desegregation plan in an appeal to the U.S. Court of Appeals for the 5th Circuit.

“Choice has worked well for the district in the last 50 years,” said Jamie Jacks, a lawyer for the school board. “The district has the most integrated classrooms of any school district in the area.”

Cleveland’s historically black high school, East Side, is still virtually all-black. The city’s historically white school, Cleveland High, is now evenly split between black and white students. The consolidated high school would enroll approximately 1,1oo students, about two-thirds black, according to court documents. The school district has argued that combining the schools would trigger a new era of white flight.

Cleveland students, parents and community members have expressed mixed reactions to the consolidation order, responses that haven’t broken neatly along racial lines.

But the school board’s decision to appeal the order did split along racial lines: Its three white members voted in favor of an appeal, and its two black members voted against, according to Jacks.

The school district and the federal government had each proposed that the community begin planning this summer in preparation for opening the newly consolidated schools for the 2017-2018 school year, which begins in August 2017. But the district said it will ask the appeals court to stay the lower court’s ruling while it considers the case; if the appeals court grants that stay, the consolidation of the schools could be delayed.

A spokesman for the U.S. Department of Justice declined to comment.

The long-running case in Cleveland is one of 177 pending school desegregation cases in which the federal government is involved, according to Justice. Of those cases, 43 are in Mississippi.