Worried, running out of options!?

Im 18, and my roommate is 19, and we always go on hikes when we can, well I wasn't able to go today so she went by herself. She left around 2 and said she will be back by 6 ( thats are normal times we hike) and she isn't back yet and its DARK! Im actually really worried! I called her and her phone is off, I called my parents and they said to just wait, that she must of went somewhere, I drove to the appalation entrance where we start and her car is still parked there? To early for cops, it hasnt been a day, gaaah im freaking?!