Final answer:
The Lewis and Clark expedition faced obstacles such as harsh weather, insects, and unfamiliar territory.
Step-by-step explanation:
The Lewis and Clark expedition had to overcome several obstacles during their journey. They faced harsh weather conditions, including fierce storms that left them wet and freezing. They also had to deal with swarms of gnats and mosquitoes as they traveled up the Missouri River. Along the way, they encountered and killed various animals, such as elk, buffalo, and grizzly bears. Additionally, they had to navigate unfamiliar territory, establishing relationships with Native American tribes and dealing with the challenges of collecting minerals and documenting their findings.