Yes, Asclepias. Maybe Asclepias sullivantii, smooth milkweed (judging by the foliage).
hortster

There are the "wild" Milkweeds and there are the cultivated Milkweeds, but both are host plants for the Monarch butterfly larva. When blossoming the wild milkweed blossoms produce a very pleasant aroma, probably meant to attract many different pollinators. Some people that would not even think of allowing the wild milkweed to grow in there garden are planting the cultivated cultivars because they are acceptable, so it depends on you and what you will tolerate whether to allow the wild cultivar to grow.

Thanks for the ID, not sure if I like it or not, but do like the idea of attracting butterflies to the garden. This milkweed grows on a very steep slope in our garden that is not part of where I grow anything so I guess I can leave it for the butterflies.