The missionaries were happy for the eight day respite at Fort William. Eliza wrote that June 19th was “the first Sabbath that we have spent in quietness and rest since the 8th of May.” Resting on Sunday was important to the missionaries, but the American Fur Company traveled 7 days a week so the missionaries had no choice but to keep going.
On June 21, they left Fort William after having rearranged their belongings into packs for the animals and the smaller wagon. They left the larger wagon behind. The fur company left all their wagons. From here on, Narcissa and Eliza would ride sidesaddle. The next goal was to reach the Rendezvous 400 miles away.
After leaving Fort Laramie the party traveled for about 5 days along the south bank of the North Platte. They reached a crossing near Casper, Wyoming but the river was too high to be forded so boats were made by stretching buffalo hides over a frame of willow branches. These were called “bull-boats” because only the skins taken from the tough old buffalo bulls were used. Imagine the time it took to stop and make the boats before being able to continue. This article shows the making of the Bull boats. http://www.womenofthefurtrade.com/wst_page15.html