SALT LAKE CITY — Rattlesnakes aren't to be trifled with, but if you're trying to collect the sounds of every creature in the West that slithers, hops, flies or flops, distance isn't a luxury you can afford.

"You get yourself in some strange situations," said Jeff Rice, a soft-spoken University of Utah research librarian who's trying to create the first comprehensive — and free to the public — archive of natural sounds in the West.

Minutes later he was squatting in the hills above the city training his lightweight parabolic microphone toward a Great Basin rattlesnake a few feet away.

The snake, caught by wildlife agents earlier in the day in a backyard, offered a few doubtful quiet moments.

Finally, though, it let loose a long, dry rattle, both eerie and fascinating, that unmistakably said keep away.

Rice, decked out in black headphones and a gray sweat shirt, grinned like he'd been given a Christmas present.

"I knew he'd come through," he said.

The recording, reduced to a short clip, will be the next added to the Western Soundscape Archive, a Web-based sound clearinghouse headquartered at the University of Utah library.

Though it's just a year old, the site already has more than 800 recordings of birds, mammals, reptiles and amphibians from 11 Western states. It'll also feature "ambient soundscapes" from wild places across the region.

The sounds will be available to teachers, scientists and anyone else interested in hearing the odd murmurings of a sage grouse, javelina, Columbia spotted frog or mountain-dwelling moose.

The landscape recordings could also provide important audio snapshots that could be used for comparison later when trying to understand how animals respond to encroaching subdivisions, oil and gas development, a warming climate or other changes.

Repeat photography can reveal changes in a limited area but repeated recordings offer broader insights, said Kurt Fristrup, a scientist with the National Park Service's natural sounds office in Fort Collins, Colo.

"A good recording survey in an area might be a couple of football fields in diameter to a couple of miles in diameter," Fristrup said.

Many of the sound clips on the archive have been donated from other recordists. Some, Rice had to go get himself.

He's hunkered down in Utah's remote San Rafael Swell to record the chatter of beavers, logged hours near Nevada's Lake Mead listening to relict leopard frogs and visited a laboratory to tape the Northern grasshopper mouse, a pint-size rodent that perches on its hind legs to offer a shrill whistle of warning.

"It's like a squeaky door," Rice said.

In the field, animals tend to be most active in early mornings and evenings. Rice comes prepared with hand-held digital recording equipment and a sense of adventure.

"You leave at 2 a.m. and find yourself wandering around bleary-eyed in a swamp," he said. "Sometimes you wonder what you're doing."

The work has its own quirky challenges — he's learned not to wear clothes that ripple noisily in the wind — and an urgent, serious side too.

As natural places disappear, so do the animal sounds that decorate them.

Geneva-based World Conservation Union estimates that one in three amphibian species is at risk for extinction.

Rice, 41, wants to capture as many as possible on tape before they're gone.