San Bernardino National Forest, California (CNN) At any moment, a plume of smoke could rise from somewhere in California's 33 million acres of forest land. The rugged terrain is often unreachable from the two-lane highways that twist through the thirsty wildland.

Several years ago, Pam Morey recalled, one of those plumes filled the skies over Big Bear Lake. Ten minutes later, a second one broke through a couple miles away. A few minutes later, a third appeared.

It was an arsonist.

But before the fire department got the call, and before anyone in town noticed smoke on the mountain, the first eyewitness was already on the case -- nearly nine miles away.

Perched over 8,000 feet above sea level, a volunteer lookout armed with standard-issue binoculars saw the columns of smoke rising, one by one, in a tidy row.

The volunteer spotted the fire from one of the few remaining fire lookout towers in the 823,000-acre San Bernardino National Forest.

At a time when firefighters make use of cutting-edge equipment like drones, high-powered aircraft and infrared cameras, old-fashioned lookout towers are still an important first line of defense in spotting wildfires.

"Nothing can replace the human eye," said Morey, the forest's fire lookout coordinator.

The San Bernardino National Forest fire lookout team has spotted 12 fires in the 2018 season alone. They range from car fires, to campfires gone awry, to fires sparked by lightning strikes.

In each case, the fires were called in and extinguished quickly -- before they could grow into one of the raging wildfires that end up on TV.

"They're what I call a $100 fire, versus the $1 million fires, like what you're getting up in Northern California," Morey said, referencing the Delta Fire which ripped through 63,293 acres in September 2018.

"We spot those little smokes," she said. "The firefighters go, they get them out, and everyone goes on their way. But any of those could have turned into devastating fires if they weren't caught quickly."

Vigilant volunteers

The Keller Peak Lookout Tower

Twice a month for the past seven years, Tony Arnieri has climbed the 28 steps from the base of Keller Peak to a 14-by-14 foot room at the Keller Peak Lookout Tower.

The steps are the home stretch of a 30-mile journey from the nearest freeway, which buzzes 6,572 feet below the mountain.

The retired information systems manager travels the last four miles on an isolated, single-lane road peppered with campsites and animal tracks. One way in, and one way out.

At the tower, Arnieri proudly opens the door to his "office" -- there are spotless windows on all four sides, and a wrap-around porch underneath a billowing flag. On a clear day, a peek through binoculars could yield a glimpse of the Pacific Ocean 100 miles away. But the day always begins with that flag.

"We put the flag up first, so we can see what direction the wind is coming from," Arnieri said. The wind speed -- coupled with temperature and humidity readings -- sets the tone for the day. Erratic winds, soaring temps and low humidity could mean a busy day for Arnieri, and the volunteers manning the six other towers.

He uses an old fashioned wet thermometer and dry bulb, pairing them with a sling psychrometer to record the humidity levels. He logs and broadcasts his findings over a dispatch radio -- connecting his information with fire authorities and forest officials on the ground. He logs occupied campsites and keeps track of expected visitors to the forest, so he is aware in case an emergency happens. But as Arnieri does this, his eyes are on the skies. "We're constantly checking for smoke," he said. "It's a good day when you don't see a fire."

Where there's smoke...

When the lookouts do spot smoke, the next challenge is to pinpoint the location of the fire.

Paul Labarrere has spotted four fires during his 17-year career as fire lookout volunteer. In one instance, he saw smoke 11 miles away from the tower -- which he later learned was a 10-foot by 10-foot fire started by a lightning strike. His accuracy in recording its location, smoke color, and size helped firefighters knock down the blaze before it could turn into a monster.

The key is the Osborne Fire Finder, a detailed, circular-shaped map of the forest, marked by each of the 360 degrees, and broken down into quadrants. Designed by a US Forest Service employee in 1915, the device requires no electrical power, and is still used to identify the apex of a blaze.

Pam Morey using the Osborne Fire Finder

By turning its base toward the smoke, the lookouts can get an "azimuth reading," which will help determine the distance of the blaze from their location. The lookout will broadcast the mileage and nearby landmarks, so fire crews can scope it out.

Labarrere's had one false alarm -- a barbecue -- but Morey stresses the motto on the mountain: it's better to be safe than sorry. Conditions can change on a dime.

When lightning hits, Morey said, it can strike a root in the ground, and it will remain there, smoldering. When the sun comes out, the warmth can ignite the root. "We mark those, and keep an eye on that area. Smoke can travel. It can hit a tree, it can go into the roots ... and come up a couple miles away."

Fewer eyes in the sky

Morey currently oversees 282 volunteer lookouts in the U.S. Forest Service's program. They come from different walks of life -- retired doctors, lawyers, fire chiefs, and teachers.

During its heyday, in the 1930s and 1940s, over 5,000 lookout towers peppered the nation's dense forest groves.

Fire lookouts were paid, and lived in the towers 24/7. "They actually had to fight the fires they spotted. They'd jump on their horse, and go put out the flames," Morey said.

Many of the lookouts were women. In the Angeles National Forest, outside of Los Angeles, a woman named Ramona handled the duties for over 50 years, Morey said. She raised her children on the mountain, living there six to seven months each year. There was no running water, or electricity. In some of the deepest regions of Northern California and Oregon, helicopters dropped off food and water for the lookouts, or they simply lived off the wildlife that crossed their paths.

Morey herself used to hike nine miles from the main road in the Angeles National Forest to staff the South Mount Hawkins lookout. She would spend the entire weekend there, by herself, sharing the forest with herds of big-horn sheep. "I never felt alone, or lonely" she said.

Tony Arineri, left, Pam Morey, center, and Paul Labarrere, right

By 1964, only 250 active towers remained, according to the US Forest Service. Budget cuts -- combined with the emergence of new technologies -- shuttered the towers.

Twenty-two original towers in San Bernardino National Forest were either abandoned or destroyed. In 1993, Morey joined a movement to restore and re-open the buildings which could be salvaged. Seven of them are currently active, and the tight-knit community rallies to keep them open.

Yet, some things never change. Volunteers are dazzled by bear and mountain lion sightings.

There's still no running water in the towers.

To make up for fewer pairs of eyes in the sky, residents and hikers are encouraged to be vigilant. Volunteers sell campfire cookbooks and canteens to raise money for maintenance. The local lumberyard provides wood to replace weather-beaten doors, and the country furniture store donates beds. For these businesses, the lookout towers are instrumental in keeping their livelihoods safe.

The effort has paid off.

That string of fires in Big Bear Lake a few years ago turned out to be a group of teenagers, Morey said. Law enforcement blocked off the roads, and waited for the group to emerge.

And the fires stopped.

But the watchful eyes are constantly on patrol.

"Once you get into this ... you get into a habit," Morey said. "No matter where you go, you're always looking."