The caches were often shaped like a jug with a narrow mouth. Six to eight feet deep, they held twenty to thirty bushels of produce, and a ladder was used to enter the larger ones. Many caches were within the lodges, while others were outside but near the lodges. The women did the work of digging, lining, and filling the caches. Gathering a long grass that grew near the river or a spring, the women bundled and dried it for use as a lining. They then dug the pit, using a short-handled scapula hoe, and laid a floor of dead and dried willow sticks evenly and tightly into the bottom. Over this, they placed the grass lining, followed by a circular piece of hide cut to fit the bottom. In the larger caches, a bull-boat cover was used. The sides of the cache were also lined with the dried grass, which was held in place by long willow sticks that were secured to the sides with pins made from willow forks. All materials were carefully dried to avoid spoilage from moisture.
According to Buffalo Bird Woman [a Hidatsa], strings of braided dried maize were placed four ears deep around the bottom of the cache pit. In the center, dried, loose grain was placed up to the top of the four-tiered series of braided strings. A string of dried squash was then piled in the center of the pit on top of the dried corn, and a second series of braided corn was placed around the edges to a height even with the piled squash. The shelled grain was again scooped in to cover the squash, and the process was repeated until the cache pit was filled. The dried squash, which was prone to rotting, was thus protected from moisture by the shelled maize, which did not spoil easily. A buffalo-hide cover, a layer of bundled dry grass, a small log puncheon, and another layer of grass and hide completed the covering of the cache pit. Finally, earth and a loose dusting of ashes and refuse were added to hide the valuable store.—Lynn M. Alex in South Dakota History, used with permission.