In its largest land deal in 17 years, the East Bay's regional park agency is teaming up with a high-tech millionaire to buy 1,476 acres of hilly grasslands and oak forests to expand Pleasanton Ridge Regional Park.

The $6.63 million sales agreement was unveiled Friday in advance of a park board vote Tuesday.

Park officials say the Tyler Ranch property land along Sunol Ridge is a recreational gem.

Rising from Niles Canyon near sea level to 2,000 or more feet, the ridge has wide dirt trails for hiking, bicycling and horse riding, and panoramic views of the San Francisco Bay to the west and the San Ramon, Livermore and Central valleys to the east.

"It has amazing views," Ayn Wieskamp, a regional park board member from Livermore, said Thursday during a visit to the property. "People are going to love to come here, but they're going to have to work hard to get up the ridges here."

As she watched, the salt ponds in southern San Francisco Bay glittered in the sunlight. A kestrel, a small member of the hawk family, flapped its wings to hover in the air over tawny brown grasslands.

Besides scenery, the land has strategic importance to the East Bay Regional Park District.

The acquisition provides another big link in long-term plans for a ridgeland hiking trail to run from Pleasanton Ridge park near Dublin to Mission Peak Regional Park in Fremont.

The land also gives the park district a rare opportunity to improve public access to the 4,000-acre Pleasanton Ridge park in the hills west of Interstate 680.

The ranch property off Foothill Road in Sunol has a flat area well suited to building a new parking lot for visitors to leave cars and start trips into the Pleasanton park.

"Flat land is hard to get," said Bob Doyle, a park district assistant general manager. "It's usually developed."

The cattle ranch, also known as Foothill Farms, had been for sale for some time, but the park district couldn't afford to do anything without help.

The Fremont-based Priem Family Foundation stepped forward this year with a promise to contribute $1.73 million of the $6.63 million sales price. As a result, the park district's share shrinks to $4.9 million.

Under the complicated sales agreement, the foundation also promises to buy 1,156 acres of the land from the district and keep it for three or more years. This gives the park district time to line up grants or other money to buy the land back at a big discount.

The park district will sell the land to the foundation for $4,500 per acre and later buy it back for $3,000 per acre.

"This is a huge bargain for the public," Doyle said.

The ranch owners also helped make the deal by agreeing to sell for below-market prices, Doyle said.

Curtis Priem of Fremont, creator and president of the foundation, said he and his wife want to protect natural lands in the East Bay.

"We love hiking and mountain biking on the land," Priem, a retired computer scientist and entrepreneur, said via phone Friday. "We're helping preserve a huge chunk of land that the public can enjoy forever."

Priem, 46, used to design computer graphics technology, and he co-founded NVIDIA, a Santa Clara-based company with 4,000 employees worldwide.

Priem said his foundation and the park district proved natural partners. His group can provide money and make deals fast, and the district can care for the land permanently, he said.

The park district is nearly out of land-buying money from a $225 million regional park bond measure passed in Contra Costa and Alameda counties in 1988.

Although the district is considering asking East Bay voters in November to renew the measure, park officials need money immediately when they buy land, Doyle said.

The new park addition will open to the public in four or five years, park officials estimate. In addition to the three years expected to complete the acquisition, it will take an additional two years to adopt a land-use plan for the park area and develop basic visitor facilities such as a parking lot.

The Tyler family and its heirs have owned the cattle ranch since the 1940s, according to a park district report. At one time, the property was owned by the family of Charles Crocker, the railroad baron and bank founder, park officials said.

Reach Denis Cuff at 925-943-8267 or dcuff@bayareanewsgroup.com.

RIDGE deal

The East Bay Regional Park District board will consider a deal to buy 1,476 acres of land for Pleasanton Ridge Regional Park when it meets at 2 p.m. Tuesday at its headquarters, 2950 Peralta Oaks Court, Oakland.