unreached vs unreachable

unreached and unreachable both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unreached	No	Yes	No	No
unreachable	No	Yes	No	No

As adjectives, unreached and unreachable are synonyms defined as:

Other synonyms of unreached include out of reach, unapproachable.

unreached (adjective)	unreachable (adjective)
inaccessibly located or situated	inaccessibly located or situated