Sounds like this location was recently logged. Having blackberries sweep the landscape is common. It is the early sucession. You likely have other species growing in there. Eventually the blackberries will be choked out, as the stand matures.
One of our woods is covered with wild red raspberries (logged about 7 years ago). The deer do love them but wow are they frustrating to work with. We mow trails through them and it helps funnel the deer past our stands. I will also say the deer ticks sure love the wild raspberries.