Set off by stark cliffs splashed in hues of brown and red, beige and buff, Cave Creek Canyon is home to an astonishing array of plants and animals.
There are pines, firs and spruce that are unthinkable in the surrounding desert. There are flame-colored tanagers and more than a dozen types of hummingbirds, drawing biologists and bird-watchers worldwide.
There also may be gold.
An international mining company has staked 36 mining claims near the canyon, setting off a battle over whether this unique slice of southeastern Arizona mountains is more valuable for its minerals or for its aesthetic and biological treasures.
"It has become one of the premier sites of field biology in the world, drawing scientists from all over the United States and abroad," Edward O. Wilson, Harvard University's Mellon Professor of the Sciences, wrote to Congress. "It is a national treasure."
Buffeted by criticism, Newmont Mining Corp., which staked the claims two years ago, has pulled back.
"We are just not going to go into the Portal area," said James F. Hill, a vice president in the company's Denver headquarters.
But he declined to categorically rule out mining--the claims remain in effect--and opponents say they cannot be sure the canyon will be safe unless a mining ban is written into law.
"To say they're not going in there now, fine, I believe them," said Rep. Jim Kolbe (R-Ariz.). "But that doesn't say what they might do in the future."
Kolbe has introduced legislation that would bar mining in 13,100 acres of the Coronado National Forest encompassing the canyon and two mineral-bearing areas that flank it. The same measure nearly passed last fall, but House and Senate versions could not be reconciled before Congress adjourned.
Hearings are scheduled for Tuesday.
What has residents in Portal--and thousands of supporters across the country--on edge are Newmont's claims next to the canyon and about half a mile from this hamlet of 150. The claims are scattered among 700 wooded acres in the national forest, overlooking some home sites.
The company's original permit would have allowed exploratory drilling of four holes up to 500 feet deep. It included building 3,000 feet of new roads, upgrading 3,000 more feet and four drill pads for a truck-mounted rig.
Opponents nationwide, envisioning huge earthmoving machines rumbling through an open-pit, cyanide-leaching gold mine on the canyon rim, waged a letter-writing blitz to urge Congress to bar mining.
In response, Newmont's Hill wrote a letter to the U.S. Forest Service in December, 1990. He noted that the area has a high potential for mineral discoveries, but said that tests had not given the company a clear basis to continue the search.
He also noted concern that mining would be inappropriate in the area and said the company would not fight efforts to forbid mining in the canyon.
If prospects for gold are uncertain, the bounty of nature is not.
The canyon, west of 9,798-foot Chiricahua Peak in the southeastern corner of the Chiricahua Mountains, is at the junction of the Chihuahan and Sonoran deserts. It's at the northern edge of many Mexican birds' range and is part-time home to rare and exotic species such as the elegant trogon.
Because temperatures drop as elevations rise, biologists in a very short distance can find a range of species equivalent to what might be encountered on a trip from Mexico to the Canadian Rockies.
That includes everything from yuccas, cacti and mescal to cottonwood, oak and evergreens. There are scores of spiders, snails, squirrels and snakes, even a small wildcat called the jaguarundi. One University of Arizona physician studies scorpion venom for its pharmacologic value.
"You can stand . . . in global fir and spruce, and if you've got a good arm, you can throw a rock across the ridge and have it land in mescal and open pine and semi-dry, semiarid brushlands . . . just within a matter of a few feet," said Alden Hayes, a retired U.S. Park Service archeologist and resident of Portal.
One reason mine opponents have set their sights on congressional protection is that they worry the government stewards of the land are inclined to allow some mining.
The Forest Service got the Bureau of Land Management to block mining in the area for a two-year period that ends Sept. 27.
But Forest Service officials have said they would prefer to regulate mining through administrative action, which would have a 20-year term, and be more easily revoked than an act of Congress.
Mike Borens, lands and mineral officer for the Coronado National Forest, is among Forest Service officials who doubt that the entire area should be off-limits to mining, particularly the land around Newmont's claim and the area around Silver Creek, on the canyon's opposite rim.
"Cave Creek is a very special and unique area," Borens said. "But the area outside Cave Creek, adjacent to Cave Creek, we're not so sure is as significant."
But opponents argue that the areas that Borens describes drain into Cave Creek, and mining there would hurt the ecosystem. And they bridle at any digging that might hurt this jewel of the Southwest.
"It's just awesomely beautiful," Kolbe said.