https://www.google.com/search?q=what%27s+the+longest+river+in+the+us&rlz=1CASFJY_enUS1018&ei=7ieRY5XxJJzAkPIPloGtyAY&oq=whats+the+longest+river+in+&gs_lcp=Cgxnd3Mtd2l6LXNlcnAQARgBMgcIABCABBAKMgcIABCABBAKMgcIABCABBAKMgcIABCABBAKMgcIABCABBAKMgcIABCABBAKMgcIABCABBAKMgcIABCABBAKMgcIABCABBAKMgcIABCABBAKOgoIABBHENYEELADOgcIABCwAxBDOg0IABDkAhDWBBCwAxgBOgwILhDIAxCwAxBDGAI6DwguENQCEMgDELADEEMYAjoFCAAQkQI6BQgAEIAEOgsIABCABBCxAxCDAToICAAQgAQQsQM6CggAEIAEEMkDEAo6BwgAEIAEEA1KBAhBGABKBQhAEgExSgQIRhgBUNABWKgqYN8-aAVwAXgAgAFfiAGuDZIBAjIzmAEAoAEByAESwAEB2gEGCAEQARgJ2gEGCAIQARgI&sclient=gws-wiz-serp&safe=active&ssui=on read it
Generally it seems Everest is considered to be in Nepal, which is what I've always heard; but I did see in looking through this and other sources that the border between the Tibet region and Nepal runs directly through the peak! Thanks for the feedback!