Generally more in the north, the south is quite rare to see.
When I went to school in Zhengzhou, I used to eat it all the time. Zhengzhou's potato noodles are made in casserole, with a special broth and shredded meat in it, and the flavor is very fresh. The potato noodles have a smooth texture and can be boiled, fried or eaten as cold as noodles.
Now a lot of supermarkets are estimated to sell, you can go to see try Oh. o (∩_∩)o....