They were pouring concrete today at the new Vikings stadium site

This Dec. 30th photo shows the construction going on behind the Metrodome after final game ever in the stadium. (Photo courtesy Earthcam)

Construction crews have hit another milestone for the new Vikings stadium.

“The concrete started today,” said Michele Kelm-Helgen, chair of the Minnesota Sports Facilities Authority, the state agency charged with building the place.

It’s actually starting a little early. Mortenson Construction vice president John Wood previously said he expected concrete work to start in mid-January.  Crews even had to halt some of the work earlier this week because of intense cold from the polar vortex.

“We’re pouring the first five, probably five to ten what they call drill shaft foundations. They’re about two feet in diameter and they’re about seven feet deep,” Kelm-Helgen said Thursday. “They drill these holes and pour concrete into them. So, eventually, all over the site you’ll eventually have about 300.”

Of course, if all goes well, you’ll never see them.

The process has about 30 months to go. The Metrodome is set to be deflated on Jan. 18.