That is, indeed, a (former) go-cart track and (current) flea market. Ya-Ta-Hey is a bastardization of the Navajo (Dine') word for "hello". It is correctly pronounced more like Yahht-e'eh, and is spelled many different ways as the Navajo did not traditionally have a written language (part of why the Code Talkers were so effective). The highway just east of it (running north-south) was formerly known as Route 666, but some folks just felt too wierd about that and it was re designated as 491 in 2002.