Before reaching the Pacific Northwest, the Lewis and Clark Expedition had to return to St. Louis for supplies.
defeat the Nez Perce in battle.
cross the Rocky Mountains.
spend the winter in Fort Clatsop.

Cross The Rocky Mountains.

Explanation:

100% sure correct if not tell me(hope it helps)

to protect the united states' role as a world leader, president truman wanted to prevent the soviet union from spreading communism beyond its post-world war ii boundaries. he declared that the united states must assist any nations struggling to prevent a communist takeover.

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