Wowzers on the Himalayans coming to America. At least in percentage there.
I'd imagine both the Bhutanese and maybe also the Nepalese are Lhotshampa; i.e. ethnic Nepalese forced out of Bhutan due to the government's exclusionary policies. Most of them went over to Nepal in the 80s and 90s, but ended up getting resettled, mostly to the U.S. as hope of return to Bhutan has become increasingly remote .
Here's a good old thread about this topic, featuring the now-departed for AAD poster Lewis Trondheim.
When I lived in Madison, weirdly enough, I encountered multiple Nepalese-Americans because apparently it's been a common place of resettlement for Nepalese refugees for the past few decades.