A tall observation tower, usually built on mountains or high ground, used by forest rangers to spot and monitor forest fires.
Compound of 'fire' and 'tower' (from Old French 'tour'), becoming common in North American forestry during the early 20th century.
Firetowers were once manned 24/7 during fire season by rangers who lived alone in small cabins 100+ feet in the air—they used binoculars and fire finders (compass-like instruments) to detect smoke miles away!
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