MOOSE (AP) - One of the two ranches still holding grazing permits in Grand Teton National Park - the only ones remaining of the 29 there when the park was enlarged - says it will not use its permit this year, but wants the option to return in 2004.

"After much thought and discussion, we have come to the decision that we will not be bringing our cattle to the Elk Ranch this summer," the Porter-Gill family, which owns the 895-acre Jackson Hole Hereford Ranch six miles south of Grand Teton, said in a May 23 letter to the National Park Service. The family cited "unforeseen events … before the family," but declined to elaborate.

The family asked for a one-year nonuse permit, which would allow it to bring its herd back to the park next year.

Most national parks do not permit livestock, but since Grand Teton was enlarged in 1950, grazing was grandfathered as a concession to ranchers and local and state officials for loss of private land.

In 1950, 29 permittees grazed about 4,230 animals on nearly 68,000 acres in the park. In recent years the numbers have fallen to about 1,450 cows and horses on 24,790 acres. Park grazing has declined steadily as leases have expired with the deaths of family members under whose names the leases were issued.

Two years ago, the Mead-Hansen family permanently pulled out due to increasing pressure from environmentalists, predators, tax laws and drought. With the Porter-Gill out for the time being, only one other operation, the Pinto Ranch, is expected to graze cattle in Grand Teton this year. Its operations are less noticeable because it relies mainly on surrounding national forest land, park spokeswoman Joan Anzelmo said.

One year without cattle "will be good for the resource," said Franz Camenzind, executive director of the Jackson Hole Conservation Alliance. "It obviously eliminates at least one year's conflict with wolves, grizzly bears and the interaction with bison and elk."

Opponents say grazing causes vegetation damage, loss of forage for wildlife, erosion, water contamination and potential conflicts with grizzly bears and wolves. They also say livestock has no place in national parks.

Supporters say grazing enables ranchers to stay profitable and stave off selling land to developers, thereby preserving open space.

A final decision on whether to allow grazing to continue in the park rests with Congress, which has extended some grazing leases that would have otherwise expired to allow time to study the issue.