What is the setting of the book New Moon and why is it important to the book?

The setting, 1960's Tulsa, OK, is very important in the book. For one, you wouldn't see gangs or "Greasers," walking around nowadays, but there could've been in the mid 20th century. Also, the location of this book is very important because it affects how they behave and act, or sometimes just how they speak (fuzz, tough, tuff).