BENTON COUNTY — Rattlesnake Mountain offers sweeping views of the historic McWhorter Ranch, a pristine property largely unchanged since it was settled in 1903, laced with dry grasses and sagebrush and home to elk and other wildlife. The ranch stretches down the mountain’s south face across more than 20 square miles of Washington’s shrinking shrub-steppe habitat.

In the not-so-far-off distance, another scene unfolds: the bustle of the nation’s fastest-growing metropolitan area, complete with high-tech businesses and newly planted vineyards to support a booming wine industry.

McWhorter Ranch is going up for sale June 1, and given its size and location, the property could very likely draw bids from agricultural and real estate developers. But state and local officials are working with conservation groups to try to raise enough money to stave off any speculators and preserve it.

“There aren’t many of these big ranches left. It’s a rarity and it’s precious,” said Jeff Tayer, regional director for the Washington Department of Fish and Wildlife. “As rare as this is now and as precious as it is now, it’s nothing compared to how rare it will be 20 years from now.”

Lucullus Virgil McWhorter traveled west from Ohio to settle a sprawling stretch of land in arid south-central Washington in 1903, raising sheep, cattle and children. He developed relationships with the Native American tribes in the area, studied their culture and helped them defend their land and water rights.

Generations of McWhorters grew up on the ranch that has become a shining example of conservation farming practices.

“It’s amazing to look around and see, not only the beauty, but how’s it been preserved,” said Max Benitz, a former Benton County commissioner and longtime family friend who’s serving as property caretaker. “It’s just a real opportunity for perspective.”

Adding to that perspective is that during World War II the federal government condemned some of McWhorter’s land — along with the land of many others — for a top-secret project to build the atomic bomb. In the process, the Hanford nuclear reservation was born, spawning a nuclear industry that produced plutonium for the nation’s weapons arsenal for decades.

Thousands of people now work to clean up the highly contaminated Hanford nuclear site. Scientific research there and at the nearby Pacific Northwest National Laboratory has spawned dozens of high-tech businesses in the Tri-Cities of Richland, Kennewick and Pasco.

In addition, agriculture remains a huge economic driver. Dozens of apple, pear and cherry orchards line the hillsides, and new vineyards are continually being planted to support Washington’s growing wine industry, ranked second nationally behind California.

Industry and jobs have boosted the region’s population beyond 260,000, and the U.S. Census Bureau earlier this year tagged it as the nation’s fastest-growing metro area since 2010.

All that growth doesn’t bode well for Washington’s shrub-steppe habitat, which is just a fraction of what it was decades ago, and the species that rely on it.

Wildlife officials see the ranch, with its deep soils and healthy plants, as an opportunity to boost populations of threatened sage grouse and ferruginous hawk, as well as a number of other species: badgers, black-tailed and white-tailed jackrabbits, Townsend’s ground squirrels, burrowing owls and pygmy rabbits.

“Shrub-steppe diversity is based on space. In a forest, you can create diversity by going up, but to enable biodiversity in shrub-steppe, you need land,” said Mike Livingston of the Washington Department of Fish and Wildlife.

Water could be an issue for anyone who wants to develop the site. The water supply for the ranch came from 13 cisterns, which were gravity fed from a natural spring higher up the mountain.

“Our experience has been that if there’s a good place to develop, whether it’s agriculture or housing, it gets developed,” Fish and Wildlife’s Tayer said. “Our idea is to focus development next to infrastructure and focus conservation on more remote areas. That’s what we’re trying to do here.”

The property encompasses some 16,000 acres broken into three separate sales. The state is focusing its efforts on the main ranch of 14,135 acres as a public recreation spot for hikers, horseback riders, bird watchers and hunters.

Public land access for hunters is key to managing an elk herd that roams between private property, the nuclear site and the neighboring Hanford Reach National Monument. The herd is estimated at 700 animals — roughly twice what wildlife managers say it should be — largely because the elk migrate during hunting season to the federal lands, where hunting is barred.

“This could be one of the largest remaining blocks of shrub-steppe that could be available for public acquisition, and the McWhorter family has been incredible stewards of the land,” said Ranch Block, director of lands for the Rocky Mountain Elk Foundation based in Missoula, Mont. “We’ve committed to help financially, but as to what the value is and what the partnership is going to look like, it’s too soon to say.”

The McWhorter family declined to comment on the impending sale. The state has set aside $1.8 million toward the purchase. An appraisal of the property is still being completed, but Tayer estimates the state will likely need at least another $3.5 million to buy just the main ranch.

McWhorter’s grandson, R.J. McWhorter, approached Tayer eight or nine years ago about selling the property to ensure it was preserved, Tayer said, but just couldn’t part with it. R.J. McWhorter died in a four-wheeler accident on the ranch. He was 86.

Now his children have decided it’s time to sell.

“My sense from the family is that they want to keep their options open,” Tayer said. “We just hope we’ll be the best option.”