Overheats after driving 70 MPH for 1 hour

Hello, that's a heck of a symptom. I would be looking at thermostat operation, as it could be sticking at times, intermittently. Also, ensure you have no restrictions within your radiator, condenser and fan - make sure air flow comes right through the radiator. If you continue to have problems, definitely recommend a professional hands on assessment. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops