id for stream side plant

Can some id this plant, please?
Plants are in the Southern Rocky Mtns (US), at 11000 ft / 3353 m along a stream.

 

That's a Veratrum of some sort, you can find distribution maps for the various species on USDA Plants.

 

Thanks, that's all i needed to find it in my Weeds of the West book.
California falsehellebore (Veratrum californicum Durand), a member of the Lily family.

 

Yes it's a False hellebore. Use extreme caution if you handle it as all parts of the plant contain deadly alkaloids!