Parks Canada says it has killed one of two bison bulls that wandered away from Banff National Park.
Officials said the animal was moving toward private grazing land and posed a safety risk to the public and to livestock.
"The decision to euthanize the bull was taken only after every other possible solution was tried or examined by highly trained, professional, and dedicated Parks Canada staff who are committed to conservation and the protection of species like bison," Christie Thomson, a Parks Canada spokeswoman said Friday in a statement.
"Public safety is a priority for Parks Canada and this decision was made in order to protect the public and to uphold commitments made to the Province of Alberta and other stakeholders as part of the reintroduction project."
Parks Canada said it made every effort to coax the bull back to the national park, where the herd of bison was allowed to roam free on July 29.
The two bulls wandered off on Aug. 5.
Staff continue to monitor the second bison bull.
"Fortunately his movements are not posing a risk to public safety or to the safety of livestock. Efforts to reintroduce him to the national park are ongoing."
Thomson said the remaining 32 bison in the herd have stayed within the reintroduction zone in Banff National Park's backcountry.
Sixteen plains bison from Elk Island National Park were reintroduced to the park in February 2017 into the remote Panther River Valley, about 40 kilometres north of Banff.
Ten of the females had calves last year and seven of those animals have now given birth again this year.
Parks Canada has said it was prepared for the possibility the bison would roam and was working closely with the province and landowners in the area.
Plains bison are an iconic part of Canada's history, having freely roamed in the Rockies, filling an important need for the livelihoods of First Nations people and early settlers.
They disappeared from the area due to overhunting before the national park was created in 1885.
Plains bison on provincial land aren't considered wildlife in Alberta.