2011 Altima steering wheel vibrates on highway. Starts at about 70mph and stops vibration at 80mph. Do wheels need balancing?

Vibrations that hit a "harmonic" at certain speeds and vanish both slower and faster are almost always balance. You can get an idea of which end has the problem from where you feel the vibration most, steering wheel means the front wheels and seat of your pants means the rears.

Thanks VStar650CL! Went to a tire shop and they said it wouldn't be balancing. I had them rotate the wheel and this morning the vibration was not at the steering wheel. It was at the seat of my pants. Will have to get a balancing!

You're most welcome. I'd be about 95% confident a balance will fix you up, but in case it doesn't, you'll want to find a tire shop with Road Force Variation (RFV) capability in their balancer. RFV uses a pneumatic roller with a set of x-y strain gauges, which allows it to load the tire at road speed and analyze exactly what the wheel assembly is doing. So it can spot and identify hidden belt, sidewall, and rim issues that a regular balancer can't.