Big Bear Lake Facts
How deep it is, how cold, how clear, and whether there are actually bears — sourced, with the disagreements between sources left visible rather than smoothed over.
The numbers
Depth, elevation, area and dimensions come from the Big Bear Municipal Water District, which manages the lake, and Visit Big Bear. On width the two disagree: Visit Big Bear publishes ½ mile, while other references list a maximum closer to 2½ miles. We're quoting the official figure and flagging the gap rather than splitting the difference.
How deep is Big Bear Lake?
72 feet at its deepest point, which sits near the Bear Valley Dam at the west end. Across the whole lake the average is closer to 35 feet — most of what you paddle or boat over is well under 40 feet of water.
Both figures assume the lake is full, and it usually isn't. Big Bear is fed almost entirely by snowmelt, so the level swings year to year and the water district tracks it as feet below full pool. On 3 August 2026 the district's gauge read 8.32 feet down from full, which takes that deepest point to roughly 64 feet and pulls the shoreline inward at the shallow east end. The district publishes that reading live; it's worth checking against any fixed number, ours included.
How warm is the water?
Warmer than people expect for 6,743 feet. The water district posts a live surface temperature, and on 3 August 2026 it read 69.9°F — swimmable without a wetsuit for most people, if briskly so on entry.
Peak summer surface temperatures generally land in the 60s to low 70s°F. Beyond that we'd be guessing: neither the water district nor the forest service publishes a month-by-month temperature table, so we're not inventing one. In winter the shallow edges and the east end can ice over, while the deep water near the dam stays open. All of these are surface readings — a few feet down it's much colder, which is what catches swimmers out.
Is the water clean? Is it clear?
Those are two different questions, and the honest answers differ.
Clean: the Big Bear Municipal Water District monitors the lake and publishes limnological reporting on it. Swimming is normal and popular all summer. Like most warm, shallow reservoirs, Big Bear can develop seasonal algal blooms, and when one occurs the district or county posts an advisory — check for a current one before swimming rather than assuming.
Clear: not especially, and it varies. This is a shallow, nutrient-rich, snowmelt-fed reservoir with a soft bottom that stirs up easily in wind and boat traffic. Expect green-tinged water and limited visibility in late summer rather than alpine transparency. That's characteristic of the lake, not a sign something's wrong with it.
🐻 Are there actually bears in Big Bear?
Yes — black bears, and they're a routine part of life here. They raid trash cans, wander through neighborhoods, and turn up on doorbell cameras often enough that locals stop filming them. Use bear-resistant bins, don't leave food in your car, and give any bear you see a wide berth.
But the valley isn't named for them. In 1845 Benjamin Davis Wilson rode in with a posse and found the place thick with grizzlies, and that's where the name came from. California's grizzlies were wiped out of these mountains by around 1906 and are extinct statewide; the black bears you'll meet today were introduced to the range in 1933. So the bear on the state flag is gone, and the bears in Big Bear are a different animal entirely.
Elevation, point by point
"Big Bear's elevation" depends on where you're standing. The valley floor sits near 6,750 feet and the surrounding peaks run to about 9,000.
Worth knowing before you arrive: at these elevations shortness of breath and poor sleep on the first night are common, especially coming straight up from the coast. Drink more water than feels necessary and save the hardest hike for day two.
🎣 What lives in the lake
Rainbow trout are the headline species and the reason most people fish here. They're stocked by the California Department of Fish and Wildlife along with the water district, which is what keeps the population up in a lake this warm.
Also present: largemouth and smallmouth bass, channel catfish, bluegill, crappie, and carp. A California fishing license is required for anyone 16 or older.
Quick answers
Is Big Bear Lake natural or manmade?
Manmade. A rock dam first flooded the valley in 1884 to supply water to citrus growers down in Redlands, and the current dam replaced it in 1912. Before that, what's now Big Bear Lake was a meadow.
Can you swim in Big Bear Lake?
Yes. Surface temperatures reach the 60s to low 70s°F in summer. McDill Swim Beach is the only lifeguarded beach on the lake — everywhere else is swim at your own risk. Compare the beaches →
Where does the water come from?
Almost entirely snowmelt off the surrounding San Bernardino Mountains. There's no major river feeding it, which is why the lake level tracks the winter snowpack so closely and why a dry year is visible from shore.
Does Big Bear Lake freeze?
Partly. Shallow edges, coves, and the east end ice over in a cold winter, but the deep water near the dam typically stays open. It doesn't freeze solid enough for ice fishing or skating, and walking out on it is a bad idea.