1 adjectives to describe wildwoods

It was a tract of a hundred miles, more or less, across, mainly unbroken wildwood, cut up by rapid rivers, impossible of navigation, otherwise than by canoes and light skiffs which could be carried from one sheet of water to another on the backs of the woodsmen, around the cascades, and over tracts of intervening land through virgin forests, without roads, and, to a large extent, without paths.

1 adjectives to describe  wildwoods