2 adjectives to describe sierra

In traversing these lofty sierras the traveller is often obliged to alight and lead his horse up and down the steep and jagged ascents and descents, resembling the broken steps of a staircase.

Through all the windings of his eccentric route, through pathless forests, across rugged sierras, along the sides of nameless streams, we shall pursue his trail.

2 adjectives to describe  sierra