Mountain Range is one. I have also heard it as a Mountain Field as well as a Mountain Stretch, but the correct one I think is Mountain Range.
Some nouns that are synonyms for mountains are:hillsrisespeaksbluffsbutteelevationrangeridgeformationvolcano
combined
not together, apart
together and conjoined
The word mountains is a noun. Some synonyms for mountains are cliffs, volcanoes, crags, mesas, mounds, and ranges. Other words related to mountains are precipices, domes, sierras, and bluffs.
join gather unite
come together, unite, join
There are many synonyms of the word drunk and the list is so long.
Mountains located closely together are called a mountain range.
A group of mountains together is referred to as a mountain range.
A group of mountains that are grouped together as a system is called a mountain range.
A group of mountains all together is called a mountain range.