The death of a young sow near Banff is a blow to the grizzly bear population in the Bow Valley, say Parks Canada officials.

A CP train hit and killed the four-year-old animal on Thursday morning just west of the townsite.

The loss of a female bear is significant, said Steve Michel, a park specialist in human-wildlife conflict.

"We were optimistic that we might see a trend where we're going to have a few more reproductive-aged female grizzly bears in the Bow Valley so this is extremely unfortunate that she's been killed in this accident," Michel told CBC News.

"Particularly difficult news for our staff here. We've sustained a high number of grizzly bear mortalities in this part of the Bow Valley over the last decade."

Trains have killed 11 grizzly bears in or near Banff National Park in the last 10 years, leaving six cubs orphaned.

In the past, bears have been killed in the same area after being attracted to grain from leaking rail cars, but Michel said that wasn't a factor in this case.