GREAT BARRINGTON — The backstory of Great Barrington-based youth development organization Railroad Street Youth Project (RSYP) may be familiar to anyone who’s been paying attention to the South County nonprofit landscape. It was 1999, and 19-year-old Amanda Root, who’d dropped out of Monument Mountain, was dismayed by the disengagement and sense of alienation she was seeing among her friends. She, along with many adults in the community, were especially upset by a spate of youth deaths. Over the course of a few years a dozen young people had succumbed to overdoses, accidents and suicides. Community members of all ages were mobilized to do something.