While researching a topic, a student has taken the following notes:
- The Clovis First hypothesis proposes that ancient humans known as Clovis were the first to populate North America.
- The Clovis arrived around 13,000 years ago.
- Stone tools found at the Fort Rock Cave site in Oregon date to approximately 15,500 years ago.
- Butchered mammoth bones found at the Jensen site in Nebraska date to approximately 22,000 years ago.
- These items support the idea that humans were present in North America before the Clovis population arrived.