Straight Up Films is developing a film based on Donnie Eichar's book "Dead Mountain" which Brandon Lee Tenney has been hired to adapt for the screen.

The story deals with Eichar's five-year probe into the unsolved 1959 deaths of nine experienced hikers in Russia's Ural Mountains - an event also known as the "Dyatlov Pass incident".

Soviet investigators had found that the hikers had torn open their tents and run barefoot out into the snow on a night in February, saying an 'unknown compelling force' had caused the deaths.

Access to the region was subsequently blocked for hikers and adventurers for three years, whilst there has been decades of speculation. Theories range from failed Soviet military experiment to even an alien attack.

"Transcendence" producers Kate Cohen and Marisa Polvino are teaming with Casey Carroll to produce the film. The story was previously the subject of the 2013 film "Devil's Pass" which IFC released in the U.