the mauling occurred in a backcountry area frequented by bears , and signs posted at trailheads warned visitors to take precautions .
fish and wildlife service , said .
the sow bear was linked to the scene through dna analysis of hair and scat samples found near wallace 's body , nash said .
evidence showed multiple bears , including the sow , were near wallace 's killing .
investigators now believe those tracks might have washed away in a rain storm that went through the area before wallace 's body was discovered .
he was hiking alone in yellowstone 's hayden valley , about eight miles ( 13 kilometers ) from where matayoshi was killed .
 
the bear was allowed to remain free after matayoshi 's death because park official said monday .
the decision to euthanize the 250 - pound ( 113 - kilogram ) female bear was meant to protect park visitors and staff , superintendent dan wenk said .