Marjie Whitehead was watering plants in her greenhouse just after noon on Saturday when she and her two dogs discovered three young grizzlies on her property near Whitecourt, Alta.

Her frantic attempts to call her dogs into the house while the bears ate dog food in her backyard root cellar were captured in a video posted to Facebook. Whitecourt is 180 kilometres northwest of Edmonton.

"Our dogs immediately saw them at the same time I did," Whitehead told CBC Edmonton's Radio Active on Tuesday. "And of course, they tore after them and started barking at them. And I froze.

"I was too petrified to even move. So once I came to my senses because of the dogs barking and whatnot, I quickly got inside the house and locked the door."

One of the young grizzlies ran at the dogs, but the dogs were unhurt.

Alberta Fish and Wildlife officers set three traps in the general area afterward and caught three grizzly bears on Wednesday morning. They can't confirm if the captured bears are the same ones seen on Whitehead's property, spokesperson Ina Lucila said in an email to CBC Edmonton.

Officers will assess the bears to determine whether they will have to be put down.

"Having a grizzly bear in an urban area is a serious public safety concern, especially when the animal is not shy of humans or willingly approaches them," Lucila said. "Bears that show this sort of behaviour are at an increased risk to injure or kill someone. For these reasons, officers may have to make the difficult choice to put a bear down to prevent future public safety problems."

Whitehead was home alone on Saturday. Her husband and son were in Edmonton.

She got her husband on the phone. He told her, "You're going to have to get the gun."

Warning shots fired

Even after Whitehead fired off two warning shots, the bears remained unfazed.

"They were so unconcerned with the noise and with the dogs," said neighbour Sean Gurnsey, who showed up with his two teenagers after being called by Whitehead's son.

"[The bears] weren't afraid of anything."

Marjie Whitehead recorded this video of grizzlies in her yard near Whitecourt, Alta. on Aug. 17. 1:14

Gurnsey and his kids managed to get the dogs into his van.

They scared off the grizzlies by driving the vehicle toward them — firing more scare shots and yelling.

The bears ran down toward a nearby creek, but returned two hours later to get into the root cellar again, which by that time had been closed.

After the bears dug into the ground around the root cellar and clawed the siding of Whitehead's home, she got her gun again — not to kill the animals, which are a threatened species in Alberta, but to scare them, she said.

"I guess because they couldn't get into the root cellar they actually went away when I fired off those three shots," she said. "I was so frightened. And now every time I walk out my front door I am leery and I look around and I'm scared."

Whitehead and Gurnsey said they've spotted several grizzly and black bears around their properties this year.

The three bears are spotted in Marjie Whitehead's backyard. (Marjie Whitehead)

"And this is the first time we've seen that in 29 years. So it's very unnerving right now," Whitehead said.

"We're kind of all on edge out here. All of the neighbours have seen these bears. They've been up on people's decks, they've been in people's yards and now obviously in Marjie's yard eating her dog food."

Alberta towns and cities have developed rapidly and many urban areas have expanded into what was, until recently, natural wildlife habitat, Lucila said.

"So it is not uncommon for residents to see wildlife in our communities. Especially at this time of year, bears are looking for food to fatten up before hibernation."