Hmm good point Xavier, yet Nate has a good point too. However i have a view aswell

.
The Wild West/Old West in America is stated to be anywhere west of the Mississippi River. As you can see in this map, it is not exactally in the centre of the US:
That may mean that the term 'Western Mudos' isn't something that is decided by political means but rather the regular inhabitants of Mudos may use the term, the same way American and other nationality citizens use Wild West. Aslo the same Wanted poster you posted states that Stranger last purchased 'A six dollar necklace...'. Oddworlds currencey (or at least Mudos') is Moolah, which suggests that there could be several or just a couple of mistakes in this poster (but there might not be

). To (sorta') back this up, in the past I have only heard Lorne or any of his co-workers mention the game as Western themed so the creator of the poster may have taken it literally. This is all just my 2 cents and just an opinion but please share yours

. Anyways, Xavier could be right but we'll never know for sure where the Mongo River is, unless OWI release a new version of the Oddworld map featuring the Mongo Valley. Seems unlikley due to recent events and projects.
P.S. Also, if it has officially been stated as the actual west of Mudos, please share the link
