It's been a year since Sports Authority announced it would close all its stores.

The company Earth Treks plans to turn its former headquarters in Englewood into a 52,000-square foot gym, claiming it will be the largest in the nation, and a larger version of a gym in Golden.

What happens to the other vacant Sports Authority locations? It's a question with no easy answer.

There are around a dozen former Sports Authority buildings in and around Denver.

Nearly two weeks ago, the city of Greenwood Village teased something is in the works. Monday, a spokeswoman would only say a retail business is moving in, but the deal isn't done.

The Cherry Creek location is now a Charlie's T-Shirts. Inside the Colorado Mills Mall in Lakewood, the competition took over when DICK'S Sporting Goods moved in, according to the Denver Business Journal.

Then there's the iconic Sports Castle on Broadway.

"I'm not surprised that we are a year out and the stores are mostly un-leased," Molly Armbrister with the Denver Business Journal said.

She says it's owned by the Gart Companies, controlled by the well-known Gart Family, which is looking into development opportunities as well as a historic designation, which could impact future plans.

"They can't tear it down or make really drastic changes to the exterior," Armbrister said.

In 2016 there were 27 Colorado properties on a bankruptcy auction list. One of them was close to 80,000-square feet.

"Very few retailers want that much space, particularly in the retail climate as it exists right now," Armbrister said "We've seen stories for the last two or three months about one retailer after the next closing stores or filing for bankruptcy."

Armbrister says gyms and fitness centers are one possibility to fill that kind of space. Dividing the space among different businesses is a possibility, though complicated.

There's still no update on a new name for Sports Authority Field. The Broncos have had discussions with companies that are interested, but so far no deal.

The Denver Business Journal says Sports Authority was paying $3.6 million every quarter to keep their name up there. That deal is no longer valid.