In that case, you are tall enough to consider some other potential candidates:
Kawasaki KLX250
Suzuki DRZ 400
Suzuki DZ 350
All of these are readily available on the used market. The two Suzukis are a little larger displacement and are perhaps more practical than a 250cc model. The Yamaha WR250R is the bees knees, with a modern engine and fuel injection. I have heard of people having it up to 90 on the highway, which is phenomenal for a 250cc bike. But it is on the market only as of the last two years, so I think there are very few available used models and they are pretty pricy. The Yamaha XT250 is also new on the market, but the XT225s outnumber them available used by a wide margin.
The final option is buying a straight dirt bike and then adding a street kit from Baja Designs, but many states are cracking down on this, and will no longer issue a street title or license plate to such a bike. You are only given offroad tags and they are not legal to ride on the street.
If I was buying such a bike primarily for dirt, and only to have enough streetability to drive from one trail to another, I would get the KLX250.