Dozens of free ranger-led programmes across the state park system every February break — guided hikes, animal tracking, maple sugaring and crafts.
Details change often — check with the program.
Listed in the GOkidOZ guide to December and February vacation camps around Boston. Registration for the December week usually opens in the autumn and the popular age groups fill first — check the official site for exact dates and availability. Also worth browsing: all school-vacation camps and the full winter guide.