Meriwether Lewis:

To port, hills falling off to arid plain.
Starboard, hills rising; and beyond,
Dark and purple mountains
Ranged one above the other
To the lofty peaks of snow.

Winds, mysterious noise,
The haunts of savages

unknown.
Day after day, mile after mile
They lie in watch,
the mountains.
We move slowly closer,
perilous
Presently we’ll turn
To assault the peaks.