WordNet records no synonym and no antonym for donner pass. It is the only member of its synset, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a mountain pass in northeastern California near Lake Tahoe; site where in 1844 some members of an emigrant party survived by eating those who had died
Synonyms, antonyms and the broader and narrower relations for donner pass come from Princeton University’s WordNet. Full sources and licences.