From GallatinMedia.org:

On February 19 at 2:51 p.m., a 9-year-old boy from Carlisle, MA was reported missing by his father.

The boy went missing near the junction of Middle Road and Lobo Ski Run at Big Sky Ski Resort.

Shortly after the report, the boy was found deceased in a tree well. He died due to blunt force injuries caused by hitting a tree on a steep slope.