What are some characteristics of the different biomes Lewis and Clark encountered as they traveled across the United States? Objective Students will understand that a biome is a large naturally occurring community of plants and animals Students will understand climate is prevailing weather conditions in an area over a long period of time Students will understand Lewis and Clark encountered different biomes and climates as they traveled across the United States. Students will be able to identify the different biomes associated with different sections of the Lewis and Clark National Historic Tra Duration: 60 Minutes.