(CNN) — The killer whale known as Lolita appears one step closer to returning to its natural habitat of the Pacific Northwest, after performing at a Miami tourist attraction for decades.

It was taken from the ocean in 1970. But after a long-running dispute over where Lolita belongs, officials from various parties announced Thursday a “binding agreement” to take Lolita — also known as Tokitae or Toki — to its “home waters.”

“Lolita will receive the highest quality care as the team works to make relocation possible in the next 18 to 24 months,” Miami Seaquarium said in a statement Thursday.

“I know Lolita wants to get to free waters. I don’t care what anyone says. She’s lived this long to have this opportunity. And my only mission is (…) to help this whale get free,” said Jim Irsay, the Indianapolis Colts owner who is helping to pay for Lolita’s move.

He said Thursday the cost could reach “eight figures.”

Whale’s tank measures 80 feet by 35 feet

Also at the press conference Thursday was Eduardo Albor, CEO of The Dolphin Company, which operates the Miami Seaquarium; Miami-Dade Mayor Daniella Levine Cava; and members of Friends of Lolita.

The Seaquarium says Lolita is 57 years old.

The orca hasn’t performed since last year but remains in its tank, which is 80 feet long and 35 feet wide, CNN affiliate WPLG reported.

Orcas can live up to 90 years, weigh up to 11 tons, and grow to 32 feet, the National Oceanic and Atmospheric Administration says.

Advocates said locations for a natural sea pen have been identified, including one in waters Lolita’s family still swims through, WPLG reported. Lolita’s 95-year-old mother is believed to still be alive.

“(There’s) the opportunity for her to acoustically connect with her family, without a doubt,” Charles Vinick, the executive director of the Whale Sanctuary Project, told the station. “So, acoustically, yes, and potentially physically over time.”

The whale will be flown across the country and housed in a natural sea pen in Washington state, where it will be monitored and taught to fish after decades of being fed by handlers.

That “hopefully will lead to eventually her getting out of the gate, getting free, getting with her pod,” Irsay said.

“We’re here because we all care deeply about the health and well-being of this beautiful creature, and I’m very happy to be here for this historic announcement to begin the process to return Toki to her home waters,” the mayor said. “So many have worked prayed and hoped for this result for many, many years. The most important thing is Toki’s long term well-being and together, guided by the experts, we’ll continue to do what is best for her.”

‘She’s going to become a symbol’

The Dolphin Company acquired Miami Seaquarium after the dispute over Lolita had begun.

Albor recalled at the press conference that his commitment to Lolita began when he took his daughter to the seaquarium, and she became upset about the whale’s captivity.

“This is beyond Lolita,” he said. “She is going to become a symbol.”

In 2015, the NOAA said it was adding Lolita to the endangered species list as a Southern Resident Killer Whale. The population was depleted between 1965 and 1975 because of captures for marine parks, the NOAA Fisheries said. The whales were added to the endangered species list around 2005.

Activists petitioned NOAA to include Lolita on the Southern Resident endangered list, saying they never had the right to separate it from designation for the Seattle killer whale population.

Captive orca Lolita set for release into ‘home waters’ after 50 years at Miami Seaquarium