Bears are waking up across the land, peering out and finding a world that looks nothing like the one they left behind in December.

At Tahoe, temperatures hit the low 60s last week and the bears are emerging from their snow caves and dens. In many areas, they are finding a snowpack so high that they have to climb trees for a view or a nap. The bears then venture to the flats around the lake, which have been cleared of snow, to search for food — including at mountain homes and cabins.

At Yosemite National Park, the valley floor has been clear of snow for weeks, and the meadows are greening up. Last week, bears were scrounging at Half Dome Village, North Pines Campground and near the trailhead for the Mirror Lake Trail. That was verified through a new website, KeepBearsWild.org, which tracks the movement of a few bears with GPS collars in Yosemite (see below).

Try to envision this transformation in the past five months across the Sierra Nevada:

Before: In the past 10 years, there have been years with no snowpack and low levels of vegetation, and many periods when bears and other wildlife had to scrounge for anything they could get. Vast miles of dead pines now span the central Sierra in a band that ranges from roughly 4,500 feet to 7,500 feet elevation on west-facing slopes; other species and elevations eluded sweeping damage. Long after much of the land is reborn, the dead pine trees will remain a reminder of drought.

After: As another storm swept through late in the week, the snowfall totals for the season topped 700 inches at Sugar Bowl near Donner Pass and Truckee. The Department of Water Resources reported verified snow depths of more than 14 feet at 7,900 feet on the flank of Mount Shasta, 20 feet at 8,250 feet on the flank of Lassen Peak, 17 feet at Lake Lucille in the Tahoe Basin, and nearly 15 feet at Bond Pass on the northern border of Yosemite. In the eastern Sierra, Mammoth Mountain reported a verifiable 26½-foot snow depth at its 11,000-foot summit.

Tahoe bears: At Homewood, nestled along Lake Tahoe’s western shore, Larry Ferguson looked out of a mountain cabin last week and saw big paw prints from a visitor the night before. So Ferguson followed the tracks. “I found him, sleeping in a tree, perched on a tiny old dead branch about 20 feet up, claws stuck deep into the bark,” Ferguson said. “He was cool enough to hang out for a short session, then crawled down to his tree-well bed for some more sleep. Tahoe’s bears are waking up and it’s a beautiful thing.”

That Yosemite website: An estimated 400 black bears (in various colors) live in Yosemite, and a first step to letting the public into their secret world was unveiled last week. Information from the website that tracks the GPS signals from collars worn by bears and locates them on a map is available at http://keepbearswild.org/bear-tracker. This is a first step, because the movements of only a few of the collared bears are made available to the public. Like many, we’d like to see all of them, of course. The data are delayed so people cannot access the information with a smartphone, then rush to the site to see and photograph the bear. One of the goals of the website is to get people to drive more slowly in Yosemite and reduce bear collisions, the leading cause of bear deaths in the parks.

Fence-top dwellers

In response to a recent story about a coyote that travels the backyards of Millbrae by walking along the tops of fences, two similar reports were filed:

•A fox was photographed by Doug Nelson in the backyard of a Mill Valley home. “I think the fox had a den under our neighbor’s deck, and all the yards are fenced, so fence-top is the logical way to get around,” he said.

•Longtime Pacifica resident Cindi Ekberg reported that a coyote has been in her backyard nearly every day for seven years. “We have watched his puppies come and go, but the first time they came in our yard was a couple years ago,” she wrote. “Last year, two of four new pups ventured into our yard through the railings of our fence and set off the motion lights.” She added: “I do not, under any circumstances, leave Kody (her collie) outside.”

Sightings

S.F. coyote: For those in other cities, the idea of coyotes in San Francisco is mind-boggling, and Michael Schneider not only confirmed that he’d seen a pair along Ashwood Lane, but photographed them sitting on terraced backyard stairs. “Max (his dog) didn’t notice,” he added.

South Bay swimmer: Along the South Bay shore at Redwood City, Joe Giammarco saw a large mammal swimming on the surface of a tidal slough and photographed it. Later inspection showed it to be a muskrat, and although that’s not a rare animal, it is rare to photograph one in the Bay Area.

Flyby: At Hidden Valley Lake near Middletown (Lake County), Dennis Morris was bass fishing, noticed a shadow, looked up and saw a bald eagle flying over him, 30 feet away.

Nature’s way: At Mitchell Park in Palo Alto, Ed Williams saw a red-tailed hawk swoop down and grab a squirrel. “Never seen that before,” he wrote. Despite the large squirrel population in the area, he then did not see another squirrel last week. “I guess the word got out.”

Good timing: At a ranger talk in Yosemite Valley last week, someone in the group yelled, “Coyote!” recounts Isabel Auerbach. “Everyone instantly forgot the presentation,” she said. “We turned around and watched a coyote stalking something, probably a mouse. The coyote then leapt in the air and came down headfirst, brandishing its tail. It probably failed, but we all felt very lucky to see it.”

Tom Stienstra is The Chronicle's outdoors writer. E-mail: tstienstra@sfchronicle.com Twitter: @StienstraTom