Craig Lee holding 10,000 year old atlatl dart
A University of Colorado research associate discovered a 3-foot-long (0.9 meter) birch atlatl dart in a melting ice patch somewhere in the mountains near Yellowstone National Park in 2007. Dating was completed recently. The dart is bowed from the impact of an avalanche and shows evidence of having been stepped on by an animal, possibly a big horn sheep.
Live Science story
National Parks Traveler story
Hat tip to Karen L. Myers.