Why did I just find Mudsdale in Poni Plains?

Question

I thought it couldn't be found there. (My game is not hacked.)

Answer 1

It is possible to find Mudsdale in Poni Plains. Nothing out of the ordinary happened.

Source

Answer 2

Well, on this website, it doesn't explicitly say Mudsdale can be found, but if you look more in depth on a different web, Mudsdale is in fact encounterable.

Source

Hope I helped! :)