SPRINGFIELD — Few things last forever, but thanks to a private-public collaboration, the south face of the Coburg Hills will stay wild for a long, long time.

SPRINGFIELD — Few things last forever, but thanks to a private-public collaboration, the south face of the Coburg Hills will stay wild for a long, long time.

John and Robin Jaqua have decided to place 1,244 acres of their McKenzie Oaks Ranch into a permanent conservation easement that will protect it from development, no matter who owns the land.

The complex deal allows the Jaquas to retain ownership of the Coburg Ridge Preserve but restricts the way they can use it.

The Jaquas received $4.9 million from the Bonneville Power Administration and $400,000 from the U.S. Fish & Wildlife Service in compensation for the restrictions. The acreage had been assessed at $6.3 million. The Jaquas will give $3.8 million to The Nature Conservancy as an endowment to cover the cost of conservation management.

The Jaquas, well-known local philanthropists, have lived on the scenic ranch nestled in a bend of the McKenzie River since 1954. The property extends across McKenzie View Drive up into the Coburg Hills in a mile-wide swath that includes prairie, oak savannah and woodland, and patches of conifer forest.

The BPA and U.S. Fish & Wildlife financed the deal to fulfill their conservation obligations.

"It's the quality and size of the habitat that makes it special," said Dorie Welch, a project manager in the BPA's fish and wildlife division. "This helps us work toward our mitigation goals."

The acreage won't be open to the public, except for occasional limited tours by The Nature Conservancy. The nonprofit agency is best known for buying property in its preservation efforts, but managing conservation projects on privately owned land is an equally useful strategy, said Jonathan Soll, the agency's Willamette Basin conservation director.

The Jaqua land is particularly valuable because it abuts a Weyerhaeuser conservation easement already being managed by The Nature Conservancy and BLM land, creating a broad swath of habitat for a range of species, some endangered and others struggling to remain viable.

The upland prairie, for example, is preferred habitat of the endangered Fender's blue butterfly and its host species the threatened Kincaid's lupine.

The oak savannah and woodlands are home to the acorn woodpecker, vesper sparrow and white-breasted nuthatch, birds whose habitat has dwindled to almost nothing in the Oregon landscape, said Soll.

Most such land has been lost to agriculture and cities in the Willamette Valley. What little remains has been overrun by the domestic grasses preferred by cattle, and invasive species such as Scotch broom and blackberry.

The conservation easement will allow managers to survey the land to see what's there and develop strategies for enhancing the traditional habitat: logging to remove Douglas fir trees that shade out oak, mowing down blackberries, reseeding with native grasses. Limited burning — a practice employed for thousands of years by Oregon natives to maintain the prairies — will be needed, Soll said.

Looking out over the meadow and oak woodlands on a windy afternoon, Robin and John Jaqua, both 86, said they wanted to find a way to preserve the pristine view, not just for themselves and their family, but for Springfield residents as well.

"It's just such a magical place," Robin Jaqua said.

She and John bought the land from the Seavey family, who had originally homesteaded there in the 1840s. By the 1950s, the bottomland was a failing hops farm, the hills above logged and mostly bare.

Hard work has turned the ranch into a tidy, productive place with cattle and sheep pasture, and hazelnut orchards along the river. The 1,200 acres north of the road have been judiciously logged and used as pasture, said son Jon Jaqua, who manages the farm.

The conservation easement allows the family to preserve the land without losing ownership, he said.

"It's an estate issue," he said. The land won't be taxed to the degree that it would be when it's handed down to the next generation, and the easement wards off potential future disputes about whether to develop it.

The view will be a valuable asset to Springfield residents, said city assistant public works director Leonard Goodwin.

"To be able to look out on forested hills — that oak savannah — is something that few people in this country have the opportunity to do," he said. "The fact that they were able to preserve it is really their legacy to Springfield."