It could be wheel balance or worn out steering joints. Have it checked by a trusted garage soon!
Wheels are likely out of balance
Most likely your tires are out of balance. Take it to a shop and have them balance them and then see how it rides.
Most likely bad tire or a wheel bent, or out of balance
It is likely a brake rotor has to much run out (warped). There could also be some problem with steering or suspension components.
Warped rotors
allignment
Steering wheel shakes
could be bad alignment
usually steering shakes over 60 mph is due to front tires needing to be balanced unless you have something more serious going on.
You more than likely bent the wheel or you threw a weight off and the tire is out of balance. Have your tires balanced. They will know if you bent the wheel.
I have seen this with bad or unbalanced tires.
Tires out of balance, bent wheel, tire defect, or suspension or steering parts worn.