Down in the thick brush along Steep Creek, biologist Mark Schwan didn't see the two brown bears until he was virtually on top of them.
"We were just above the upper bridge," Schwan said. "We were mucking around in the stream and we turned around and the two bears were right there across the stream."
Schwan was uneasy even before he saw the bears. A state fisheries biologist, he's surveyed sockeye and coho salmon in Steep Creek and Mendenhall Valley streams since 1980 and he knows black bears frequent the area. On Oct. 22, he was just off the well-used Trail of Time, near the road to the glacier.
Brown bears not complete strangers to Valley
There goes the neighborhood
"It's brushy - you can be so close to a bear, it's so closed in," Schwan said. "You don't really want to be carrying a firearm in there, with the people and all, so we've had to be really careful in there."
Schwan yelled at the bears and said they wandered up the bank. It was the first time Schwan had seen - or even heard of - brown bears in the Mendenhall Valley.
Brown bear sightings are extremely rare in the valley but this fall was an exception. A mother bear and her nearly-grown cub spent about two months ranging between Steep Creek, near the Mendenhall Glacier Visitor Center on the east side of Mendenhall Lake, and the lake's west side. Virtually every trail in the area was closed to hikers.
The closure didn't eliminate encounters, in part because some people disregarded the warnings. On Nov. 28, a woman was charged by the bears on the Moraine Ecology Trail, which was closed and posted with signs.
"People have been coming out looking for the bears," said U.S. Forest Service Naturalist Denise Wolvin, who works at the glacier visitor center. "I've had people going through the fences, ignoring the signs and going onto the trails I have closed off."
Some residents, such as Mark Kaelke and his young daughter, enjoyed a view of the brown bears from the safety of their car as the pair fished in Steep Creek near the road.
Two brown bears were seen briefly in the same area last fall and biologists suspect they are the same animals. Wolvin said if they return next spring, the plan is to trap and relocate the bears.
The cub is almost as large as the mother and biologists think it's about 3 years old.
"My guess is that's a male cub," said biologist Kim Titus, regional supervisor for the state Division of Wildlife Conservation. "In cases where the bear cub appears almost as big as the female, the mother is a small female and the cub is a male."
Titus has captured and handled brown bears, and said they differ physically and in their habits from region to region. There are exceptions to the general rules, but usually female brown bears in Alaska sexually mature at about 7 years old. Bears are considered cubs until they are about 3, then sub-adults until they are about 6. Mortality is greatest with young bears, but if a bear survives to maturity it can live to be about 25 years old.
"A 700-pound bear in the spring will be a 900- or 1,000-pound bear in the fall."
-- state biologist Kim Titus
Most mother bears chase off their cubs after about two years, but the Mendenhall mother is an exception. About one-quarter of brown bear mothers keep their cubs until they are 3 1/2 years old. This depends on factors such as the availability of food, the age of the mother and pressure from males.
"There aren't that many brown bears in the area," Titus said. "So she has no physiological incentive to come into breeding condition if she doesn't have other male bears near her. She's not in the thick of some big brown bear population."
The cub will stick with mom until she chases him off.
"He's not going to leave her, she has to boot him out," Titus said. "Or a male will come in and that will force the whole situation."
According to the Forest Service, as of Friday afternoon, the most recent sighting of the bears was Dec. 3, when a work crew for the nonprofit group SAGA saw the pair in the Dredge Lakes Area. Before that, on Dec. 1, an ice skater on Mendenhall Lake saw the bears walking the beach near Skaters Cabin.
"I'm really surprised they're still out," said Forest Service biologist Don Youkey. "If there's a food source, some bears may hang out. But usually they den up by mid-November."
The Mendenhall bears are not the only brown bears in the area still up and active. A brown bear with a cub mauled a Juneau man Wednesday at Piling Point on Admiralty Island about 15 miles west of the glacier visitor center.
The bears have been feeding heavily on the cohos in Steep Creek, putting away calories for their long winter fast. A brown bear can lose hundreds of pounds during the winter, weight that it must regain the following year.
"A 700-pound bear in the spring will be a 900- or 1,000-pound bear in the fall," Titus said.
Cohos were still in the creek last week but the recent freezing weather has made the fish harder to reach.
Biologists said most brown bears are in their dens by Thanksgiving. No single factor makes it clear to bears when it's time to den up. It's likely a combination of available food in the fall, quantity and quality of food available in the spring and summer, the amount of daylight and the weather. Adult male bears usually go into their dens latest and emerge earliest.
When the Mendenhall bears decide it's time, they'll head up either Nugget Creek or McGinnis Creek, to the subalpine or alpine elevations, biologist Youkey suspects.
Brown bears generally den up high in the alpine. Black bears generally den at lower elevations. Both species dig dens but also will use "found" sites. Excavated sites are less likely to be re-used because of potential of collapse.
Youkey said the Forest Service will reopen the trails once a full week has gone by without a sighting. He said the snow should make it easy to spot tracks if the bears are still active.
If the Dec. 3 sighting proves to be the most recent, Wolvin said the trails could open Monday. Since the snowfall last week, sledders and skiers have been active on the lake and on the hills around the visitor center.
Riley Woodford can be reached at email@example.com.