MIAMI (AP) — More than 50 years after the orca known as Lolita was captured for public display, plans are in place to return her from the Miami Seaquarium to her home waters in the Pacific Northwest, where a nearly century-old, endangered killer whale believed to be her mother still swims.

An unlikely coalition involving the theme park’s owner, an animal rights group and an NFL owner-philanthropist announced the agreement during a news conference Thursday.

“I’m excited to be a part of Lolita’s journey to freedom,” Indianapolis Colts owner Jim Irsay said. “I know Lolita wants to get to free waters.”

Lolita, also known as Tokitae, was about 4 years old when she was captured in Puget Sound in summer 1970, during a time of deadly orca roundups. She spent decades performing for paying crowds before falling ill.

Last year the Miami Seaquarium announced it would no longer stage shows with her, under an agreement with federal regulators. Lolita — now 57 years old and 5,000 pounds (2,267 kilograms) — currently lives in a tank that measures 80 feet by 35 feet (24 meters by 11 meters) and is 20 feet (6 meters) deep.

The orca believed to be her mother, called Ocean Sun, continues to swim free with other members of their clan — known as L pod — and is estimated to be more than 90 years old. That has given advocates of her release optimism that Tokitae could still maybe have a long life in the wild.

“It’s a step toward restoring our natural environment, fixing what we’ve messed up with exploitation and development,” said Howard Garrett, president of the board of the advocacy group Orca Network, based on Washington state’s Whidbey Island. “I think she’ll be excited and relieved to be home — it’s her old neighborhood.”

The agreement among Irsay; Eduardo Albor, who heads The Dolphin Company, which owns the Seaquarium; and the Florida nonprofit Friends of Toki, co-founded by environmentalist Pritam Singh; still faces hurdles to gaining government approval.

The time frame for moving the animal could be 18 to 24 months away, the group said, and the cost could reach $20 million.

The plan is to transport Lolita by plane to an ocean sanctuary in the waters between Washington and Canada, where she will initially swim inside a large net while trainers and veterinarians teach her how to catch fish.

She will also have to build up her muscles, as orcas typically swim about 100 miles (60 kilometers) per day, said Raynell Morris, an elder of the Lummi Indian Tribe in Washington who also serves on the board of Friends of Toki.

“She was 4 when she was taken, so she was learning to hunt. She knows her family song,” Morris said. “She’ll remember, but it will take time.”

The orca would be under 24-hour care until she acclimates to her new surroundings.

Caretakers at the Seaquarium are already preparing her for the journey, officials said.

The Dolphin Company took ownership of the Seaquarium in 2021. It operates some 27 other parks and habitats in Mexico, Argentina, the Caribbean and Italy.

The legacy of the whale roundups of the 1960s and ’70s continues to haunt a distinct group of endangered, salmon-eating orcas that are known as the southern resident killer whales and spend much of their time in the waters between Washington and Canada.

At least 13 orcas died in the roundups and 45 were delivered to theme parks around the world, reducing the Puget Sound resident population by about 40% and helping cause problems with inbreeding that remain a problem today.

Today only 73 remain in the southern resident population, which comprises three familial groups called pods, according to the Center for Whale Research on Washington state’s San Juan Island. That’s just two more animals than in 1971.

Animal rights advocates including People for the Ethical Treatment of Animals have long fought for Tokitae to spend her final years back home in a controlled setting.

Activists often protest along the road that runs by the Seaquarium, which they’ve referred to as an “abusement park.” PETA says it doesn’t want Lolita to suffer the same fate as her partner Hugo, who died in 1980 from a brain aneurysm after ramming his head repeatedly into the tank’s walls.

Albor said Thursday that back when his company was acquiring the Seaquarium, he and his daughter visited as tourists. He said his daughter became upset while watching Lolita’s show, even as many other in the crowd were squealing in delight.

His daughter told him “this place is too small for Lolita” and made him promise to help the orca if his company bought the park.

“It has always been our commitment at The Dolphin Company that we place the highest priority on the well-being of the animals above all else,” Albor said. “Finding a better future for Lolita is one of the reasons that motivated us to acquire the Miami Seaquarium.”

Miami-Dade County Mayor Daniella Levine Cava called the relocation plan historic, saying, “So many have hoped and prayed for this result for many, many years.”

The Seaquarium opened in 1955 on Virginia Key east of downtown Miami. It features a variety of creatures including dolphins, sea lions, manatees, reef fish and sharks, and was the filming location for 88 episodes of the “Flipper” TV series as well as movies in the 1960s.