The Forlorn will focus on that doomed group of pioneers known as the infamous Donner Party. On their way to California, these pioneers get stuck in what is now Donner Pass. With the beating snow and the quickly depleting food supply, a smaller group called the Forlorn Hope (hence the film's title) whip up makeshift snowshoes and attempt to find help. Their food runs out, many die, cannibalism occurs. Those that remained finally find help and a number of relief efforts are made to save the pioneers at camp. The first group was lucky, weak, but lucky. After that, starvation again led to cannibalism and by the time the final relief effort reached the camp, only one man was alive.
There is no word on who Glover will play, but the rest of the cast, led by Christian Kane (Lindsey from Angel), have their roles listed on IMDb. However, the list of character names doesn't reflect a lot of the Wiki summary and timeline, so I'm not sure if these names are actual Donner Party people, or made-up characters. Whatever the case, it should be an interesting and creepy tale -- but one I doubt will be a true and thorough examination of the story.