The banks of the Shennong Stream have been inhabited since at least the Han Dynasty; the primary ethnic group of the river valley has been the Tujia people. Early history of settlement in the Shennong Stream Gorge is evinced by the hanging coffins stowed in clefts on the high vertical limestone clefts; it is a puzzle to modern man as to how the heavy coffins were stowed on such steep, ostensibly inaccessible places. The coffins themselves were typically carved from a single layer section of a tree trunk, which was approximately 90 cm in diameter; although the lid section was split off to be separate. Some of these coffins can be seen presently from canoes traveling along the Shennong Stream. The coffins are typically 30 to 150 metres from the bluff top above and 25 to 70 meters above the river surface. Most commonly a coffin rests on two sturdy hewn poles that have been wedged within limestone cleft or cave to form generally level platform. Many of these coffins have been lost or destroyed due to the Three Gorges Dam construction, which has led to inundation of many of these river reaches; some coffins, however, have been retrieved for cultural presentation and archeological study. For example, one such coffin was retrieved about 10 km west along the Yangtze River mainstem and is preserved on display at Baidicheng, within an historical Daoist Temple situated high above the inundation level along the Yangtze.