While (most) LUG lists on the Web are well-maintained, likely they don't list every LUG. If considering founding a LUG, I suggest, in addition to consulting these lists, posting a message to comp.os.linux.announce, comp.os.linux.misc, or an appropriate regional Usenet hierarchy, inquiring about nearby LUGs.

Joining the group may be better for reasons of unity and solidarity. Greater numbers almost always means greater power, influence, and efficiency. The point is that starting a LUG is a significant undertaking, which should be commenced with all relevant facts and some appreciation of the effect on other groups.