The basic reason of inventing such a product was to provide an instant boost of energy. Sometimes chocolate is also added to the mixture. This, apart from improving the taste, adds more carbohydrates to the mix. It is mostly eaten by hikers and adventurers. Small quantities of gorp can be taken as a snack.
Since the mix contains so many ingredients, the packaging becomes tough. Chocolate packaging needs material which can withstand high temperatures. Dry food packaging needs to keep the aroma of the ingredients intact. But the most important is granola packaging.
Since this mixture is somewhat similar to granola, the packaging is also likewise. Zippers can be used to make the pouch reusable. Often hikers take a bigger pouch of trail mix. They keep taking out small quantities from the bigger pouch. Thus, the mixture can be preserved and used later on with zippers.
Make sure that you focus on packaging as much as you focus on manufacturing the product. This will help you to attract a larger number of customers.