A 13-mile northerly extension of the Blue Line light rail corridor keeps moving forward, with a new office in Crystal now opened for planners.

The extension of the Blue Line, which now runs between downtown Minneapolis and Bloomington, would take the light rail trains north, through Minneapolis, Golden Valley, Robbinsdale, Crystal and Brooklyn Park.

Planning and engineering is expected to continue through 2018, with building occurring 2018-2020 and a projected opening in 2021.

The new office opened last month in the Crystal Gallery Shopping Center, officials said, “making it convenient for the public and project partners to attend meetings.”

Current plans call for 10 or 11 stations on the extension, which would connect downtown Minneapolis (and the rest of the Blue Line to the south, and the Green Line to St. Paul) with the communities to the north and such destinations as the Target North corporate campus, North Hennepin Community College, downtown Robbinsdale and Courage Kenny Rehabilitation Institute, officials said.

Often called the Bottineau Line or Transitway, the extension has been under discussion since the late 1980s.