The period during which the bow and arrow became the primary weapon varies greatly by region, despite the ancient origins of this invention. Research has shown that on the western coast of North America, the bow became the dominant weapon about 1,400 years ago.

The transition from using spear-throwers (atlatls) to bows and arrows is considered one of the major technological shifts in human history. The bow was invented in Africa more than 70,000–100,000 years ago, but its spread across different parts of the world was uneven. Evidence suggests that when the ancestors of Native Americans began settling North America around 15,000–16,000 years ago, they used spear-throwers, although they were likely familiar with the bow as well.

In the central part of North America, bows began to be used about 4,400 years ago, but they did not completely replace the atlatl—both types of weapons were used in parallel for thousands of years. In other regions of the continent, the bow and arrow did not become the main weapon for a long time.

The study of this process is complicated by the poor preservation of organic materials from which bows, arrow shafts, and spear-throwers were made. As a result, researchers often rely on indirect evidence, such as the shape and weight of stone points, which introduces some uncertainty. Previously, there were various hypotheses about the early introduction of the bow to the continent and its gradual spread from north to south.

For analysis, data from 140 radiocarbon dates obtained from 136 samples of shafted weapons from the western part of North America were collected and studied. The samples were divided into two categories: arrows (bow) and atlatls. Geographically, the finds were grouped into two major zones along the 55th parallel: the northern zone (territories of Alaska and Yukon, where samples were recovered from melting glaciers) and the southern zone (from northern Mexico to California and the American Southwest, where items were found in dry caves).

The analysis showed that bow and arrow technology appeared in both studied zones of western North America almost simultaneously—about 1,400 calendar years ago. These findings do not support the model of a centuries-long spread of the technology from north to south. Instead, the results indicate a rapid dissemination of the weapon across a vast area, likely due to cultural connections among indigenous groups.

In the southern region, the introduction of the bow led to the swift and almost complete disappearance of the atlatl. In the northern zone, both technologies coexisted for more than a thousand years.

This difference is explained by a strategy of technological diversification: in harsh seasonal conditions and unpredictable resource availability, hunters preferred not to abandon proven tools but to expand their arsenal. The atlatl could retain advantages for hunting certain animal species or during specific seasons, complementing the bow.