According to TMZ, it is thought that Legeno had been hiking in the national park himself when he came into difficulties.
The area is notorious for its extremely high temperatures during the summer months, and Inyo County Sheriff's Department has indicated in its initial reports that they believe the actor died of heat-related issues. A coroner's investigation is pending.
The actor played Fenrir Greyback in the Harry Potter movies
Legeno, who was a successful mixed martial artist, also starred in Guy Ritchie's Snatch, Batman Begins and EastEnders.
He is survived by his daughter Wendy.
Rob loves his boy bands and has worked with most of them. When it became too hard to work in Australia with the media - he started POPrepublic.tv. Giving a voice to the pop culture scene for over 16 years (check dates depending on when you read this.) In his other life he is a creative director, film maker, photographer and designer... but pop is his one true love. Along with imaginary boyfriends, Nick Lachey and Channing Tatum (his husband approves).Website: www.robmanser.com