Some scholars date the origin of native cultures in the southwestern United States to immigrants who crossed the Bering land bridge from Siberia to Alaska, approximately 10,000 B.C. Others maintain that native cultures came to the Americas as early as 25,000 B.C. These immigrants settled in what is present-day southern Utah and Colorado, Arizona, New Mexico and northern Mexico. This culture area is contiguous with the Far West Culture, the Plains Culture (to the northeast) and the southern part of the Eastern Woodland Culture.