The San Francisco 49ers are going into the theme park business, investing in a $70 million deal to buy the Great America theme park -- and bumping out of the way one of its biggest opponents to building its new stadium in Santa Clara: the park's current owner.

While the team already provides its share of ups and downs on the field, taking control of the roller coasters next door to the planned $1 billion stadium gives the Niners a chance to blend football and thrill rides into one of the Bay Area's biggest attractions.

Jed York, the 49ers president, cheered the deal in a statement Monday, saying it creates "great synergy and collaboration between two of the largest family entertainment destinations in the region."

The team wouldn't reveal whether it plans to integrate Jim Harbaugh with Planet Snoopy -- but teaming up with a San Francisco real estate firm to buy Great America will pay off immediately on one front: eliminating the park's owner, Cedar Fair Entertainment, and its lingering lawsuit to hold up the $1 billion stadium deal.

Santa Clara stadium backers have sparred with the park owners since the 49ers and city officials began negotiating a South Bay stadium deal five years ago.

Rave reviews

In a statement, JMA Ventures, the real estate firm heading the Great America purchase, praised the prospect of pairing Great America with the 49ers stadium, a stark departure from public comments by Cedar Fair officials who have expressed concern that an NFL stadium could damage the park's business and create parking headaches for park patrons.

Santa Clara Mayor Jamie Matthews was enthusiastic about the 49ers' role in buying the park, saying it seems like a "natural" to him. "I could see a family having tickets to an NFL game," Matthews said, "and some people in the family going to a football game, and some going to the park."

Matthews wasn't privy to the details of the new park ownership, but said he believed the park would be open on football game days during the season, which ordinarily stretches from August through January. Nowadays, Great America is open during the fall for weekends through October. Cedar Fair had balked on that point, fearing it would suffer lost parking slots on game days.

Dennis Speigel, president of International Theme Park Services and a leading national expert on theme parks, said the involvement of the 49ers and the stadium could be a crucial boost to Great America's business. Likening the arrangement to Six Flags amusement park next to the Texas Rangers' ballpark in Arlington, Speigel said such arrangements establish a "critical mass" of entertainment spending in one area.

"It's definitely, definitely, definitely a positive," he added. "It's not a negative."

Barring stumbles in securing financing, the 68,500 stadium is slated to open for the 2015 season.

The level of the 49ers' investment in Great America has not been disclosed, but officials familiar with the deal say the price tag was tied to the park's revenue estimates, and sealing the sale allows the team to secure crucial control over how park operations relate to the stadium. As one official close to the negotiations put it, "There isn't much here that doesn't meet the eye. It is what it is."

Years of negotiations

The Great America sale, and the 49ers' involvement, is hardly a surprise -- the team has been negotiating with Cedar Fair to purchase the park for years and closed-door discussions on the topic have been a regular item on the Santa Clara City Council agenda.

And regardless of the change in ownership, the Drop Tower Scream Zone and the Demon rides aren't going anywhere, as the city's ground lease with the park owners, which generates $5 million per year for Santa Clara, calls for a theme park on the property. The 49ers have already expressed hopes of integrating other stadium-friendly businesses in the area, including former 49ers quarterback Joe Montana's plan to build a luxury hotel and restaurant complex nearby.

Cedar Fair, a Sandusky, Ohio-based amusement park operator, bought Great America in 2006, and expects to use the cash from the sale to reduce its debt problems. Cedar Fair almost sold its amusement park business in 2009 for $2.5 billion, but the deal collapsed.

Santa Clara officials must approve the transfer of the ground lease to VMA, and Matthews hinted the city might consider a rent increase. He vowed there would be no decrease in the park's rent as a result of the sale.

JMA could begin operating the park in the final three months of the year, although, as a real estate company, the outfit could retain an experienced park operator, including Cedar Fair, to continue running Great America. The company, perhaps best known for its Lake Tahoe resorts such as Alpine Meadows and Homewood, says it will keep all of Great America's current employees.

For its part, Cedar Fair executives said in their own statement that the sale was done with mixed emotions.

"Our decision to divest of our California's Great America park was not an easy one," said Dick Kinzel, Cedar Fair's chief executive officer. "This is a quality park that has terrific employees and serves a strong market."

Contact Lisa Fernandez at lfernandez@mercurynews.com or 408-920-5002. Contact Howard Mintz at hmintz@mercurynews.com or 408-286-0236.