Asclepias speciosa is an extremely important part of the Monarch Butterfly's lifecycle providing both food and shelter. The decline of this plant in North America is directly tied to the decline of the Monarch Butterfly. If you have Milkweed on your property near Durango, please, leave it there. See the article below about the Zink's efforts to do just that in the Animas Valley. Unfortunately, the huge colony that you see in the photos here that was near Trimble Crossing has been bulldozed to widen the road. Unfortunate. This particular Asclepias is never far from water, unlike its drier cousin, A. asperula, which is host to a completely different yet equally important set of native pollinators. 

https://www.durangoherald.com/articles/citizen-scientists-enlisted-to-research-monarch-butterfly-mystery/