Many diverse Native American cultures developed across the different geographic regions of North America. Why?

This is primarily due to the vast differences in climate and ecology. Depending upon the food sources, the seasons and the various challenges to daily life, different skills and traditions were valued. For instance, while in the temperate forest of the eastern part of the continent (what is now New England and the East Coast of the United States), there were plentiful deer, turkeys, fish and other game animals to hunt, so the rites of passage and skills developed around training young men to hunt these animals. This included skills with tracking, stealth and the bow and arrow. In contrast, in the far western north of the continent (what is now Alaska and western Canada), food had to be carefully gathered during the fleeting summer months and saved and the primary source of protein was the large mammals of the ocean - whale, seal, etc. Therefore, the skills and traditions valued here were those related to hunting the large ocean animals - crafting a water-tight boat, the harpoon or javelin, sailing, navigation, etc.