CHICAGO (AP) — Chicago Mayor Lori Lightfoot has presented three options for renovating Soldier Field, the home of the Chicago Bears.

Lightfoot on Monday proposed fully enclosing the stadium by rebuilding both end zones with columns that can support a dome; rebuilding both end zones with columns to make the stadium dome-ready; or modifying Soldier Field to be a multi-purpose stadium better suited for soccer.

The mayor’s office estimated the costs of the three options would range from $900 million to $2.2 billion. It didn’t say how it would pay for any of the options.

“Soldier Field must be a year-round destination,” said Lightfoot during a news conference. “We must enhance the fan and visitor experience, and that is precisely what we aim to do.”

“And we are going to keep making the case to the Bears, the NFL and the public that a revitalized Soldier Field makes the most economic sense for that storied franchise.”

The Bears have purchased property in the Chicago suburb of Arlington Heights, and earlier this year they announced that is the only location they’re considering for a new stadium.