Of all the many river confluences in the United States, where one river flows into another, only a few produce what Dr. Sublett calls an “offspring river.” In these cases, two named rivers join to produce an offspring whose name is different from those of the parent streams. A nearby example of an offspring instance would be the confluence of the Des Plaines and Kankakee to produce the Illinois River. This research endeavor involved searching all 50 states for offspring instances and then trying to determine why the name of one parental river did not continue downstream beyond the junction, as well as special circumstances relevant to each river birthplace. Overall, Dr. Sublett identified 71 offsprings. An article about the results of the research, “Offspring Rivers in The United States,” appears in the September 2018 issue of Names: A Journal of Onomastics.