What did Herbert Hoover head up? What did he rely on?

Herbert Clark Hoover (August 10, 1874 – October 20, 1964) was an American politician, businessman, and engineer, who served as the 31st president of the United States from 1929 to 1933. A member of the Republican Party, he held office during the onset of the Great Depression.

Explanation:

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain

the soviet union wanted to impose communist governments in eastern europe.