SCOTTSDALE, Ariz. — The four-year ordeal to keep baseball at Coors Field for three more decades proved to be a new experience for Rockies owner Dick Monfort. On Wednesday, he agreed to extend his club’s lease at the ballpark through 2047. But not without difficulty.

“The days of municipalities building new stadiums without financial help from clubs is over,” Monfort said Thursday. “When Coors Field was built, it was built by the taxpayers and that’s the way it went back then. It’s a different world now. We had to figure out the best way to offset some of the costs.”

The Rockies and the Metropolitan Baseball Stadium District, the state division that owns Coors Field, agreed on a 30-year lease that will cost the club $200 million. Major League Baseball approved the long-fought deal early Wednesday morning. And Coors Field, already the third-oldest ballpark in the National League, was ensured a longer life.

But to make the financial arrangement work, the Rockies horse-traded with the District for a 99-year lease on a plot of land directly south of the stadium. Now the Rockies are in the real estate business.

Metro area taxpayers, through a 0.1 percent sales tax, ponied $162 million for the construction of Coors Field, which opened in 1995. The District did not want to ask the public for more money. But the original 22-year lease was set to expire Friday. If the Rockies and the District failed to agree, the lease would have rolled over for five more years, then five again, with three possible extensions.

Monfort was not interested in moving the team or the stadium, he said. But he needed to figure out a way to pay for upkeep.

“Our only option was to figure out a long-term lease,” Monfort said. “We could have gone through three five-year deals and let the park deteriorate knowing that in 15 years we may be out or relocate. But we wanted to stay where we’re at.”

Coors Field will be 53 years old at the end of this lease. But unlike football stadiums and basketball and hockey arenas, baseball stadiums often increase in value and prestige with age. Wrigley Field and Fenway Park are each more than 100 years old.

The public owns Coors Field, but the Rockies are responsible for its survival. Monfort, and his brother Charlie, became primary owners of the Rockies in 2005, a decade after Coors Field opened. They inherited the ballpark as it aged.

The Rockies and the District each gathered engineering studies that suggested stadium upkeep over 30 years would cost about $200 million, for everything from sewer lines to wireless internet and concrete sidewalks. This season, after a three-year effort, Coors Field will have new seats throughout the stadium.

The Rockies, Monfort said, have immediate plans for improvements. The 10-year-old scoreboard above left field will be replaced before next season.

“The software that runs that, we are so far behind everybody else, it’s a joke,” Monfort said. “We’re worried things will break down. We have a real concern.”

As part of the deal, the Rockies bargained for control of a surface-level parking lot next to Jackson’s Denver sports bar, south of Coors Field. The land is zoned by Denver for an eight-story building and a variety of uses. Monfort said he wants to build something baseball-related.

“I’m not a developer by any means, so I’ll have to forge forward,” Monfort said. “But we can make it something that is really unique. My goal is to have it as an extension of the stadium.”

Monfort said he has scouted several cities and how teams have expanded the stadium outside its gates, including St. Louis, where the Cardinals built a “Ballpark Village” entertainment area next door to Busch Stadium.

His first idea, Monfort said, is to build a hall of fame. The Rockies have a large storage area at Coors Field for baseball memorabilia that is rarely seen, even by people who work for the club.

“Baseball stadiums really have the ability to last for a long time,” Monfort said. “They can gain in popularity. It makes sense to keep it up, and it saves a (heck) of a lot of money. We have a great park already, if we can enhance it, I’m excited.”