Gem of an Isle : Conservation: Each year Santa Cruz Island attracts 200 volunteers. They perform a range of chores for the Nature Conservancy.

William Elfstrom, a 69-year-old Sherman Oaks businessman, stepped from a private plane with his wife, Shirley, onto the short, grassy landing strip on Santa Cruz Island after a 20-minute flight from Camarillo.

“Sure a lot quicker than crossing the channel on the Navy boat from Point Mugu,” Elfstrom said to Jim Sulentich, the Nature Conservancy official on hand to greet the couple for the weekend.

It was a weekend for work around the island, and Elfstrom quickly inquired as to what chores might be the top priorities. The list ranged from a jeep patrol of the island perimeter to surveying bird populations to mending fences.

There were two empty seats on the Nature Conservancy charter flight, so the Elfstroms had a rare opportunity to fly to the island for their weekend outing.

Usually, they come to Santa Cruz by Navy boat several times a year for a few days, as do 200 other Nature Conservancy volunteers from as far away as San Francisco and San Diego.

The Navy has a small communications base on an island mountaintop maintained by a dozen technicians as part of the Pacific Missile Test Range. Navy boats transfer personnel back and forth from Point Mugu and provide transportation for Nature Conservancy staff members and volunteers.

The volunteers bring their own food and sleep in an old cowboy bunkhouse at the main ranch on the island, Elfstrom said.

“This is a unique place and we are here as volunteers to keep it that way,” he said. “We meet and work with volunteers from all walks of life. About a dozen volunteers are on the island at any given time.”

Driving from the airstrip to the island’s main ranch, Sulentich, the local program director for the Nature Conservancy, said the 54,500-acre Santa Cruz Island is the largest of more than 1,000 preserves nationwide run by the private, nonprofit conservation group.

Since its establishment in 1951, the Nature Conservancy has set aside 3.5 million acres in 50 states to save plants and animals from extinction. The Nature Conservancy is the largest private sanctuary system on earth.

Santa Cruz Island, 24 miles long and seven miles at its widest point, is about 22 miles off the Ventura coast. It was a private ranch from 1839 to 1987, when Dr. Carey Stanton, its last owner, died.

His dream of preserving the island for future generations was fulfilled when nine-tenths of the island became controlled by the Nature Conservancy. It is one of 46 Nature Conservancy preserves in California.

Only a few people live on this vast sanctuary on the sea: five Nature Conservancy staff members, the dozen Navy technicians, and UC Santa Barbara ecologist Lyndal Laughrin and his wife Ann, who operate the UC Santa Barbara research station here.

Yet this private holding within the boundaries of Channel Islands National Park is seldom visited. Tom Melhan, National Geographic staff writer, recently spent time on the island doing research for a forthcoming book, “America’s Least Known National Parks.”

“Santa Cruz Island is the gem of the entire Nature Conservancy system. It’s a living example of undeveloped America,” Sulentich said.

Santa Cruz is a lush, tranquil island split by a valley between two mountain ranges. In addition to the land controlled by the Nature Conservancy, a much smaller portion is controlled by the National Park Service and a private family.

The valley has been the ranch headquarters for 150 years. Situated here are brick and adobe structures, a winery, the main ranch house, a cowboy bunkhouse, stables, blacksmith and wagon shops. Off in a special corner is a century-old tiny chapel with stained-glass windows, a tower and bell.

The island is dotted with towering eucalyptus groves, stands of Bishop pines and Santa Cruz Island ironwood, found only here and on neighboring Santa Rosa Island. It’s an island of gentle slopes, steep canyons, rugged irregular hills and bold, steep volcanic cliffs spilling into the sea.

For more than 6,000 years, Chumash Indians lived here. When Juan Rodriguez Cabrillo sailed to the island in 1542--50 years after Columbus discovered America--there were about 2,000 Indians living on Santa Cruz, the largest and most topographically diverse of the eight Channel Islands off Southern California.

Many hills and slopes in remote areas of the island are denuded from nearly two centuries of foraging by wild sheep and pigs. From 1978 to 1987 more than 34,000 sheep were shot and killed here, left for birds, animals and insects to feed on.

“The sheep were having an unbelievable impact on the island. It was a tough decision, but it was the most humane and most economic way of ridding the island of the sheep,” Sulentich said.

“At last it’s beginning to pay off,” Sulentich said. “The rare and endangered plants are beginning to come back thanks to the removal of the animals.”

The Nature Conservancy’s prime motivation for buying Santa Cruz Island was because of 10 rare and endangered plants on the island.

Sulentich drove the jeep to a small field on an island bluff where 21 malacoth annus are growing, an attractive reddish-pink, knee-level shrub found nowhere else in the world. There were only nine of the plants on the island before the March rains.

Then Sulentich drove to two rocky outcroppings five miles apart to point out the world’s only Hoffman’s Arbis, 41 white-purple flowers of the mustard family, up from 21 last year.

Dotted with creeks, springs, two year-round flowing rivers and two mountain ranges with peaks 2,434 and 1,500 feet high, the island has produced wildlife that varies dramatically in size and appearance from similar species found elsewhere, ecologist Lyndal Laughrin said.

“The endangered island fox is the size of a house cat. On the mainland the gray fox is the size of a dog. The island’s scrub jay, on the other hand, is 30% larger than the jay on the mainland and much bluer in color,” said 48-year-old Laughrin, for 20 years resident manager of Santa Cruz Island’s UC Santa Barbara research station.

“On the mainland the scrub jay lives four or five years; on the island the bird lives 15 to 18 years. Most fox don’t make it past three on the mainland while the island fox live to be 8 to 10 years. It’s the difference in habitat, predators and diseases,” Laughrin said.

As many as 40 scientific researchers from universities throughout California and the nation--from as far away as Harvard and Yale and the University of Florida--stay at any given time at the UC Santa Barbara center while doing research on island flora and fauna.

“It’s a complex island with great diversity in species. Botanists, biologists, entomologists and scientists from various disciplines have a field day here. An entomologist was recently here studying the 100 species of bees and wasps on the island,” Laughrin said.