How to pronounce Arkansas

Inspired by a mistake just heard on German radio, I thought I’d discuss the correct pronunciation of Arkansas. The correct British pronunciation is [ɑːkənsɔː], whereas the correct American pronunciation is [ɑːrkənsɔː] or the less common [ɑːkənsɑː]. You can listen to the first two variants here. Importantly, in all of these variations, the s at the end of Arkansas is silent. The letter a in the syllable –sas is either pronounced as in the word saw [ɔː] (listen here) or as in the word start [ɑː] (listen here). The mistake made on the radio was to pronounce Arkansas as [ɑːrkænsəs], with –kansas pronounced just like the state Kansas (listen here). However, according to the Longman Pronunciation Dictionary, this pronunciation is only (but not exclusively) used for the Arkansas River.