River Sioux has no famous person on record yet
Waterloo has the most of any town in Iowa: 61. After Waterloo, the next longest list in Iowa is Iowa City’s, with 54. Famous people are on record for 455 of the towns in Iowa.
Who’s listed here
Famous people come from Wikidata (people whose birthplace is River Sioux), checked against each person’s English Wikipedia article and ranked by how many Wikipedia languages cover them. Nobody born in River Sioux has passed that check yet, and nobody born within 35 miles is listed.
From Wikidata and Wikipedia: people whose birthplace is River Sioux and whose English Wikipedia article agrees, ranked by how many Wikipedia languages cover each person. People known mainly for crimes, and adult performers, aren’t listed. “The usual town” = everyone born in the towns gathered so far.