Thanks for the info However I think there is still a real question here I believe your evidence that Mount Lassen is the most common local name of the mountain where local means people who live nearby However that does not make it necessarily the most common name of the mountain among all English speakers In looking at the intent of the relevant guideline I think that is what is key but I could be wrong In fact I would say that easily the more common name among all English speakers or even all Americans is Lassen Peak It is the name that is more commonly used in published literature about the mountain by a large factor AFAIK so this is how most Americans know it Added to that is the fact that it is the official name which I do think counts for something  An example suppose that everyone living near a mountain calls it by a local nickname but visitors from elsewhere guidebooks state and federal descriptions all call it by a different name Using the local nickname as the article title would be inappropriate since the vast majority of people looking at Wikipedia would not be familiar with that name I dont want to disparage the Mount Lassen appellation as just a nickname but it seems to me to be a similar case However I admit it does seem strange in some ways not to use a common local name I would suggest waiting a few days to see if there is more input on this question before doing any more moving around to avoid unnecessary editsreverts