NAMI of Sullivan County, NY Share: Human Services NAMI of Sullivan County, NY Visit Website Request Info 20 Crystal Street Monticello, NY 12701 (845) 794-1029 (845) 796-4390 (fax) Facebook About Map About A local mutual support, advocacy, self-help groups and individual members at-large dedicated to improving the quality of life for people with serious mental illness & support for their families. What's Nearby? Distance: 5 10 15 20 25 50 mi.