在明帝國北邊的國境線外,丘陵與草原、沙漠之中,有著鹽、青草、人參、松子、木耳、蘑菇等物資,又有猞猁、野馬、麋鹿、黃羊、黃鼠、鵰、魚類等動物。雖然法律規定軍民不得私自穿越邊界,但這些物資與動物就在不遠之處,基於僥倖的心理,常出境採集與狩獵,但有時難免被敵人所擄獲或傷害。這種現象,直至明朝末年依然存在。另一方面,邊境之外也有許多可耕地,明朝中葉以前,軍民常在上面墾殖;十五世紀中葉以後,蒙古勢力往南移動(特別是進入鄂爾多斯地區),界外耕種的危險性與日俱增,故其例子越來越少。至1570年代,因與俺答汗等蒙古部酋達成和解,北京以西邊境的戰事減少,出邊耕種的可能性增加,但相關記載卻不多見。
Outside the northern border of the Ming Empire, there were salt, grass, ginseng, pine nuts, wood ears, mushrooms, and other natural resources in the hills, grassland, and desert. There were also lynx, wild horses, elks, Mongolian gazelles, ground squirrels, eagles, fish, and other animals. The law forbade soldiers and civilians to cross the border. However, hunters and gatherers often crossed anyway, hoping they would not be caught. Sometimes, they were captured or injured by Mongols. This situation lasted until the late Ming Dynasty. Additionally, soldiers and civilians alike often cultivated crops just outside the border up until the middle of the fifteenth century when Mongolian forces moved south (especially toward the Ordos region). At this point, it became increasingly dangerous to farm outside the border, and therefore there were fewer such cases. In the 1570's, Beijing reconciled with the Mongolian leader Altan Khan, and border wars west of Beijing decreased, increasing the likelihood of farming outside the border.