Blame it on a western drought, making it hard for the bears to find the usual nuts and berries.
"They're looking for food and water anywhere they can find it which, unfortunately, a lot of times is in people's back yards," says Carl Lackey of the Nevada Dept. of Wildlife.
And sometimes, it's right inside people's houses, reports CBS News correspondent John Blackstone.
At Lake Tahoe, Anne Bryant of the BEAR League, explains what happens when a hungry bear gets into the kitchen.
"The first thing they do is, they head for the refrigerator. They get the ice cream," she says. "They love the ice cream."
As bear mothers teach their cubs there's easy food where humans live, the number of problem bears gets bigger.
While a year old bear sitting comfortably above a picnic ground can seem rather cuddly, Lackey sees something more dangerous.
Lackey has had to capture more than 70 bears this year, and it can be a challenge.
When one bear in downtown Reno climbed dangerously high, after getting hit with a sedative, Lackey's team tried to prepare a soft landing. The drowsy bear didn't cooperate, hitting the ground with a thump. The bear and the bear chasers survived.
Once the 325-pound bear wakes up, the goal will be to give him a very bad impression of human hospitality.
Lackey calls it aversion training, hoping barking dogs and gunfire will make a bear think twice before the next time it heads into town.
Some of the youngest bears seem to have no idea they should fear humans. With bears getting bolder, people have to learn to growl back says Bryant.
"I go out and say, 'You get out of here! This is my house. This is where I live, this is my den,'" she yells.
For years, humans have been moving into the places where bears live. Now the bears seem to be striking back -- making their move into human territory.