escarpment
He saw the road rise steeply off into the distance.
No, steep is not an adverb. This is an adjective and occasionally a verb.The adverb form is steeply.
Mountain
mountain
the coastline?
mountain
a slip face
Steeply? a cliff maybe?
The Zambezi River
i think is hill
a waterfall
This ridgeline rises steeply to a much higher altitude.