The State of Sioux (/suː/; Yuma German: Ziuks, /ˈziːʊks/), officially the State of Nadouessioux-Ñibraske (/ˈnæːdʊ.əˌs(j)uː nɪˈbræskiː/), is one of the 11 first-order subdivisions of Rio Blanco. It was the last state to be formed in Rio Blanco, as it was established in 1894, after being separated from Yuma. It has a population of 87,789, making it the least populated state of Rio Blanco.