Already been said several times that there ain't no mountain in SotS, just a small hill which is more of a mound.
There ain't no flood or river journey in SotS.
The actual ride is not mountainous, it's only a 50' drop.
The drop in the ride represents being thrown into a briar patch, it is not meant to represent plunging down a mountainous river.
The name of the ride can (and most likely will) drop the "Mountain" appellation (which it shouldn't have had from the beginning, but was given just to mirror Space Mountain's name).