FIELD, B.C. -- Rescuers in Yoho National Park are releasing more details about the search for a young Calgary boy swept to his death in the Yoho River in southeastern British Columbia.

Parks Canada spokesman Lisa Paulson says the 11-year-old and his nine-year-old brother were jumping on rocks at the edge of the fast-moving river on Friday evening when both youngsters tumbled into the water.

She says a 14-year-old relative was able to grab the younger child, but the older boy was swept away by the powerful current.

Paulson says frantic family members were able to track the child for a short distance, while quick-thinking bystanders formed a watch on bridges and embankments downstream in hopes of spotting him, but he was not seen again.

Paulson was the incident commander during the search that continued until Tuesday morning, when the boy's body was found 13 kilometres downstream at the junction of the Yoho and Kicking Horse rivers.

She says the family has travelled to Golden to identify the body and the coroners' service is now handling the case.

There have been past incidents involving kayakers along the same stretch of river, known for its extreme rapids, but Paulson believes this is the first death of a visitor in the area near Takkakaw Falls, northeast of Field, B.C.

"It was a tremendous, heroic effort," Paulson says of the teenager's efforts to rescue the 11-year-old in the moments after he fell.

She also applauds the efforts of the bystanders who tried to track the boy downstream.

"There was some very quick thinking and good judgement on behalf of visitors who did that initial search effort."

Paulson has spoken to the boy's parents and says they have an extended family and tremendous support from the community.

While there was great disappointment the boy wasn't found alive, she was relieved that the body was found quickly.

"It can take weeks or sometimes months ... but finding him now provides the searchers with some relief in knowing we can help provide the family with some closure."