In a remote area north of Bangor, a group of college students eagerly wade through sticky wet snow and climb over downed trees for a sight most people will never see.

An occasional scent of pine fills the thick forest air as the worst blizzard of the year blankets the state with snow. Evergreen branches sag from the weight. The large, white snowflakes highlighting dark green fir and pine needles make the scene look like a Currier and Ives print. The line of curious people tromping through the woods is getting closer to the destination. A dense thicket shelters the young people from cold winds.

Everyone forgets how wet and cold they are, however, as soon as they see those big blue eyes and those tiny pink noses belonging to three bear cubs, born more than six weeks ago as their mother slept for the winter.

In a small secluded gully covered by a few blown-over trees, a 142-pound female black bear lies perfectly still from a shot of a drug that keeps her aware but immobilized. State biologists Randy Cross and Jennifer Higgins had located the secluded den about 15 minutes earlier and jabbed the sleeping mother bear with a syringe attached to the end of a 6-foot pole.

A little head not much bigger than a baseball and with pointed ears and a golden-brown furry face peeps up over its mother’s thick, silky, jet-black fur and squeals. Soon, the heads of two other little cubs pop up before a captivated audience. There are two females and one male cub.

This is the sight that Karen Stainbrook of Dolgeville, N.Y., and 16 other Unity College students who are studying wildlife biology and ecology had waited years to see.

“I’ve read about them, but I’ve never seen a bear before and to see the babies too,” says an excited Stainbrook, a senior. “I have always wanted to see a bear hibernating.”

Craig McLaughlin, a state biologist and the Bear Study Project leader, along with Cross and Higgins, reaches into the den and lifts out the young cubs, who each weigh less than 5 pounds. Many hands reach out to take the shivering babies, who soon find warmth under heavy winter jackets. The anxious cub holders had been advised before their trek into the woods not to wear any perfume, cologne or scented deodorant that could be detected later by the mother bear’s keen sense of smell.

As Stainbrook goes to tuck one of the cute little cubs into her jacket, it suddenly poops on her, but the expulsion doesn’t bother the student.

“The poor little guy was scared and cold,” she says. “I just got him at a bad time.”

One of the cubs is handed to me, and its tiny little claws latch onto my wool sweater under my jacket. Its pounding, little heartbeats slow as it curls up. Cuddling its tiny head under my chin, the cub’s pink nose, about the size of a small button, feels like an ice cube as it brushes my neck. No teddy bear was ever this cute.

The college students aren’t the only ones excited about seeing the bear cubs and their mother hibernating in a den. It is just as exciting for McLaughlin and Cross, who have visited hundreds of black bear dens as part of the Department of Inland Fisheries and Wildlife’s Bear Study Project. Unlike most biologists who are able to study critters only from a distance, these biologists get real close to their subjects.

“You get to actually touch them,” McLaughlin says. “That is what is so interesting about this job.”

The mystery of bear hibernation has intrigued scientists and biologists for years. As masters of winter survival, black bears can sleep between four and seven months without eating, drinking, urinating, defecating or exercising. Mothers actually give birth to their cubs while they are asleep.

During hibernation, a bear’s heart rate drops from between 40 and 70 beats a minute to only about eight or 12 beats a minute. Body heat escapes very slowly through a bear’s thick, insulated pelt, allowing their metabolism to slow to about half of its normal rate so they can survive long cold winters. By maintaining a body temperature above 88 degrees Fahrenheit, a sleeping black bear, who remains partially alert, can react to danger much quicker than other hibernators, whose body temperatures might be less than 40 degrees.

Living off fat stored up for long winters, a bear’s cholesterol level is more than twice as high as most human’s. But bears have no known problems with the hardening of arteries or the formation of gallstones. In the winter, bears produce a bile juice, called ursodeoxycholic acid, that helps them avoid gallstones. This acid from bears has dissolved gallstones in humans, eliminating the need for surgery, according to some medical studies.

Bears don’t urinate for months. The waste product is broken down, and the nitrogen from it is reused to build protein. The ability of bears to build protein while fasting allows the animals to maintain their muscle and organ tissue through the winter. They only use up their fat.

State biologists like McLaughlin, who has studied Maine black bears for the past 14 years, have learned a lot more than just management information about bears. They have learned that a bear’s denning times and reproductive cycles are closely intertwined.

Female black bears are typically 3 to 5 years old before they first mate in the summer. Through a process called delayed implantation, the fertilized egg divides a few times and then floats free in her uterus for about six months. Its development is detained until she enters a den to hibernate.

Through summer and the fall, bears eat to gain as much weight as they can for the long winter ahead. More than 75 percent of their diet includes berries, flowers, grass, herbs, roots and all kinds of nuts. They also eat small decaying animals, fish, ants and other insects as well as honey.

McLaughlin says they can gain as much as 2 pounds a day and can feed up to 20 hours a day. Bears may go into hibernation as early as September or as late as December depending on their fall food supply and weather conditions.

If there is not much food available, bears in northern Maine, who depend on beech nuts as a primary food source, may go into their dens early, but if there are plenty of nuts and the weather is right, they may not hibernate until December.

When its time to hibernate, black bears will choose a burrow, rock crevices, hollow trees or excavated depressions under fallen trees or brush piles for their dens. A hibernating bear, whose fur is thickest on its back, neck and sides, will sleep in a curled up position to reduce heat loss from its belly and other thinly furred areas of the body.

When a pregnant female bear begins hibernation, the embryo will attach itself to the uterine wall, and after about eight weeks — sometime in January or February — cubs will be born. But if the female does not have enough fat reserves stored up to take her through the winter, the embryo will not implant and will be reabsorbed by her body.

Female bears typically have two or three cubs, which are born blind and nearly hairless and weigh between 8 and 12 ounces each. In a few weeks, the cubs will open their big blue eyes, which will turn brown when they get a little older. Through the winter they will nurse on their mother’s very rich milk. The cubs will be weaned by summer, but will stay with their mother for about a year.

Bears can stand and sit. Standing helps bears see and smell. They have color vision, acute hearing and a keen sense of smell. They learn quickly and can remember feeding locations for years. They can climb trees, bend and open car doors and pry out windshields. They readily swim to island campsites. They adapt their lifestyles to the availability of food, often becoming nocturnal to avoid confrontations with humans.

Biologists say black bears can injure or kill people, but they rarely do. Some bears have been known to leave their cubs to flee from people, but mother bears also can be very protective and have been known to attack people who get between them and their cubs.

Some old-timers say that if you play dead, a bear will ignore you or leave you alone. Biologists say, however, that that’s not true and actually is the worst thing to do. The best things to do are yell and make a lot of noise, wave something like a towel or cloth, bang pans together or run away.

For more than 20 years, biologists have gathered information about the state’s black bear population, which is estimated to be between 22,000 and 23,000. More than 50 female bears wear radio collars that send out beeping signals, allowing wildlife experts to track them. Every year, biologists visit the dens of these sleeping bears and record information about size, age and physical condition.

Reaching in the den, the biologists lift out the sleeping bear onto a tarp. Rope cuffs are placed on all four of her paws. The biologists then slide the tarp over the snow to a small opening a few feet from the den, and the sleeping mama is lifted into and wrapped up in a sleeping bag.

McLaughlin constantly checks the bear’s eyes and puts his hand up under her armpit to check her heartbeat. Opening her mouth, the two biologists check her teeth. Her pink-colored gums tells them she is in good health.

They measure her neck, chest and the length from the tip of her black nose to tip of her short tail. Her radio collar, made of a rubberized material, is adjusted. State biologists first captured and placed a radio collar on this mother bear on June 16, 1993, says McLaughlin.

Placing one of the spring scale hooks through a metal ring on the rope cuffs and another hook on the handle of an axe to be used as a cross bar, McLaughlin and Cross lift the mother bear while Higgins records her weight. Next, the babies are weighed in small canvas bags. These three range in weight from 4 1/4 to 4 1/2 pounds. Then, with nary a yelp, their ears are pierced with bright-red number tags.

With all of the information logged, it is time to put mom and her babies back into the den. But first, Cross dips his finger into a small bottle of cedar wood oil and rubs it on the sleeping bear’s nose, so when the immobilizing drug wears off later, she won’t ever know that a group of intruders held and cuddled her babies. The two biologists place the mother bear back in her den and tuck the tiny little cubs against their mother’s warm belly.

The college students watch quietly and then gather up brush and place it on top of the open den to give the mother bear and her three babies a little more cover from the falling snow.

One of the tiny little heads pops up again.

It’s hard to turn and walk away, but I have to trust that Mother Nature will protect them as she has for centuries.