As cell phones, iPods and laptops creep steadily into every corner of modern life, America's national parks have stayed largely off the digital grid, among the last remaining outposts of ringtone-free human solitude.
For better or worse, that may soon change.
Under pressure from telecommunications companies and a growing number of park visitors who feel adrift without mobile-phone reception, the airwaves in such grand getaway destinations as Yellowstone National Park may soon be abuzz with new wireless signals.
That prospect has given pause to a more traditional cohort of park visitors who cherish the unplugged tranquility of the great outdoors, fearing an intrusion of mobile phones — and the sound of idle chatter — will diminish their experience.
Some have mixed emotions. Stephanie Smith, a 50-something Montana native who visits Yellowstone as many as six times a year, said she prefers the cry of an eagle to ring tones.
But she also worries that future generations may lose their appreciation for the value of nature and the need to preserve America's outdoor heritage if a lack of technology discourages them from visiting.
"You have to get there to appreciate it," Smith said. "It's a new world — and technology is a part of it."
Balancing the two aesthetics has emerged as the latest challenge facing the National Park Service as managers in at least two premier parks, Yellowstone and Glacier national parks, consider recent requests to install new telecommunications towers or upgrade existing ones.
There is no system-wide rule governing cellular facilities in the 300 national parks, national monuments and other units the agency administers nationwide. Wireless infrastructure decisions are left up to the managers of individual park units.
The agency's mission statement requires it to protect park resources and the visitor experience, but each individual experience is unique, said Lee Dickinson, a special-uses program manager for the Park Service.
"I've had two visitors calling me literally within hours of each other who wanted exactly the opposite experience: One saying he didn't vacation anywhere without electronic access and the other complaining he was disturbed by another park visitor ordering pizza on his cell phone," Dickinson said.
Can you hear me now?
Wireless supporters say more is at stake than the convenience of casual phone conversations. Cellular providers say new wireless infrastructure will boost public safety by improving communications among park rangers and emergency responders.
They argue that the ability to download smartphone applications that can deliver instant information on plants and animals will also enrich park visitors' experiences.
"Our customers are telling us that having access to technology will enhance their visit to wild areas," said Bob Kelley, spokesman for Verizon Wireless, which is seeking to install a new 100-foot cell tower at Yellowstone.
Rural communities that border the national parks also stand to benefit from enlarged cellular coverage areas.
On the other side of the debate, outdoor enthusiasts worry that bastions of quiet reflection could be transformed into noisy hubs where visitors yak on cell phones and fidget with electronic tablets, detracting from the ambience of such natural wonders as Yellowstone's celebrated geyser Old Faithful.
Expanding cellular reception may even compromise safety by giving some tourists a false sense of security in the back country, where extremes in weather and terrain test even the most skilled outdoorsman, according to the National Parks Conservation Association.
Tim Stevens, the association's Northern Rockies director, said distractions like meandering moose already challenge the attention of motorists clogging park roads at the height of the summer tourist season.
"People brake in the middle of the road to watch animals. The added distraction of a wireless signal — allowing a driver to text Aunt Madge to say how great the trip is — could have disastrous consequences," he said.
Yellowstone already offers some limited mobile-phone service, afforded by four cellular towers previously erected in developed sections of the park.
But vast swathes of America's oldest national park, which spans nearly 3,500 square miles across the states of Wyoming, Montana and Idaho, still lack wireless reception in an age dominated by Wi-Fi and iPad users who expect access even in the most remote locations.
Park officials see definite signs that a portion of the roughly 3 million annual visitors to Yellowstone, which crafted a wireless plan in 2008, are finding the lack of cell phone coverage disconcerting.
Park spokesman Al Nash said he routinely fields calls from anxious relatives of Yellowstone visitors unable to contact their loved ones.
"They say, 'My gosh, my niece, daughter or parents went to Yellowstone, and we haven't heard from them for three days,'" he said.
(Reporting and writing by Laura Zuckerman; Editing by Steve Gorman)