Complex sentence: Since Anaheim peppers originated from New Mexico, they are also sometimes known as New Mexico peppers, where they are often referred to simply as "chiles" because they are so ubiquitous.
Split into simpler sentences: Since Anaheim peppers originated from New Mexico, they are also sometimes known as New Mexico peppers. Additionally, in New Mexico they are often referred to simply as "chiles" because they are so ubiquitous.