A Note on Spelling
This peak is spelled with either one or two "n"s in the first syllable, and both versions of the name are used often. The USGS maps show both names—the name with 2 “n”s is on the Cornwall map, near the summit, but the Maybrook map only shows one “n”. One guidebook says that the state park has 2 “n”s and the mountain itself has only one.
When I do a Google search on +"Schunemunk" I get 22,600 results, and +"Schunnemunk" gets 37,500 results. Wikipedia prefers one "n", but Summitpost prefers 2, as does the federal GNIS database, which is pretty official but can be buggy sometimes.
This mountain is perhaps the most curious case of one with 2 spellings, with no clear evidence that one or the other is definitely correct--the ketchup/catsup of peaks.