Time when people are thought to have first arrived in North America?

Native Americans have been in North America for thousands of years. Some historians believe that the Vikings and the Chinese arrived in North America well before the first Europeans. Columbus, contrary to actual teaching, didn't reach North America but the island of Hispaniola . He had no idea what existed approximately 90 miles away from where he was located.
The first humans to North America arrived by crossing a land bridge from modern-day Russia somewhere between 30,000 and 11,000 years ago.