In order to haul six dugouts and baggage around the falls, they had to build two wagons. Slabs from a 22" cottonwood tree were cut for wheels. Harnesses were made and strapped to the men who were to pull the wagons. When the wind was favorable, the sails were raised on the dugouts to help the men move the wagons across the rugged prairie. The pirogue was too large to portage. It was dragged ashore and left below the falls. More baggage was cached near the lower portage campsite.

The portage required four round trips and two weeks to complete. However, the party remained at the falls for an additional week completing construction on a collapsible iron-fram boat which Lewis designed and had built at Harper's Ferry during the summer of 1803. But they were unable to find the necessary pine pitch to seal the hides, and they did not have the proper needles to sew the hides together. In its place they built two more cottonwood dugouts.

Today Crooked Falls below Rainbow Falls and Colter Falls above Rainbow Falls are submerged.

Row 1--#1 & 2-The Great Falls, #3-carp in pool below falls, 4-5' in length, #4-Row 2--#2-Rainbow Falls, #3 & 4-Black Eagle Falls, #6-Row 3--#3-information about the portage, #4 & 5-Sacajawea Spring, #6-Electricity on the Missouri River. Row 4--#1-3-a model kitchen was built on the island below The Great Falls dam to advertise electricity, #4-6-how buffalo in the area helped the expedition.