Approximately how long was the land

bridge that humans crossed over into the americas?

Answer: 1,000 Kilometers (620 miles)

Explanation:

Historically, it formed a land bridge that was up to 1,000 kilometres (620 miles) wide at its greatest extent and which covered an area as large as British Columbia and Alberta together,[2] totaling approximately 1,600,000 square kilometers (620,000 square miles).