VALENCIA — Development giant Newhall Land & Farming Co., which built Magic Mountain in the early 1970s, is planning a 400-acre addition to the venue that would include a movie special-effects attraction, a retail-entertainment complex and hotels.
The project, nearly four times the size of the existing theme park, has been under study for more than two years. Newhall Land hopes to complete planning for it over the coming year, said Marlee Lauffer, a spokeswoman for the company.
"We are still in the very early stages of putting these ideas together," Lauffer said. She declined to go into design or financial details.
Environmentalist Lynne Plambeck said it was too soon to say if there would be opposition to the project, but expressed general concern about too much development in the area.
"It's really too bad," said Plambeck of Santa Clarita Organization for Planning the Environment. "Because that I-5 corridor is so beautiful, and it's all just going to go away."
The expansion, which would cost hundreds of millions of dollars, would intensify competition in Southern California's multibillion-dollar theme-park industry at a critical time. Attendance at the region's largest parks--Disneyland, Knott's Berry Farm, Sea World, Universal Studios and Magic Mountain--has fallen 6.5% over the past two years, to 29 million in 1998.
And the competition is getting more intense. A new park, Legoland, opened this spring in Carlsbad. Universal and Sea World in San Diego are opening pricey new attractions this summer. And Walt Disney Co. is building a $1.4-billion second park in Anaheim, while Knott's has plans to add a water-slide park in Buena Park.
Newhall Land built Magic Mountain in the early 1970s and sold it in 1977. The park is now owned by Premier Parks Inc. of Oklahoma City, which bought the Six Flags chain last year.
Premier Parks executives were not available late Friday to discuss plans for the new attraction.
Lauffer said Newhall Land is coordinating with Magic Mountain's operators as it develops its plans, but would not elaborate.
Magic Mountain is known primarily as a regional attraction catering to young thrill-seekers, billing itself as having the West's hottest collection of roller coasters.
To broaden its appeal to families with young children, Magic Mountain will open Bugs Bunny World this season.
In 1995, then-owner Six Flags California opened Hurricane Harbor, a water park that operates during warm weather and which requires a separate admission charge. The number of slides was doubled in 1997.
In making an additional expansion to Magic Mountain, developers would be following the model of theme park operators such as Disney and Seagram Co.'s Universal.
Disney, which has 47 square miles of theme parks, hotels, malls and other projects in Florida, is building a second attraction beside Disneyland: Disney California Adventure, including a 750-room hotel and a retail, dining and entertainment center called Downtown Disney.
And Universal has been gradually opening a similar complex beside its existing studio-themed park in Florida, including a version of its CityWalk outdoor mall, plans for five hotels and the Islands of Adventure theme park.
The addition to what is now called Six Flags Magic Mountain would be in a V-shaped parcel wrapped around the park's western and southern borders. The area is wedged between the Golden State Freeway on the east, a PGA championship golf course that Newhall Land plans to build on property to the south and the proposed Newhall Ranch housing project to the west.
"We're trying to look at the property and find out what's the most exciting thing we can do there," Lauffer said. "We're definitely focused on themed entertainment, and playing off of the people who already come to Magic Mountain."
Theme park consultant Ray Braun of Economic Research Associates in Los Angeles said his firm did some early planning on the theme-park expansion and has just been hired again to perform financial feasibility studies for it.
Braun said the special-effects attraction would be far less ambitious than a full-fledged Disney or Universal park. He said the complex instead would probably contain a mix of modest attractions designed to have strong regional appeal.
"What to do in that area and how to bolster the destination value of that area has been something they've studied for a long time," Braun said.
Plambeck, the environmentalist, said she was concerned about the use of public funds to widen roadways and accommodate the traffic the development will generate.
Newhall Land has been developing a huge swath of land in north Los Angeles County near the Ventura County line, including large master-planned tracts in Valencia and the Valencia Town Center retail and entertainment complex.
Its plans for the hugely ambitious 21,000-home Newhall Ranch, the largest residential project ever undertaken in Los Angeles County, have been challenged recently in lawsuits contending the development would devastate the Santa Clara River and provide too little affordable housing.
Times staff writer Martha L. Willman contributed to this story.