New Mexico was most valuable to both the Union and the Confederacy because a. it was viewed as fertile farmland. b. it was seen as economically more advanced than California. c. it provided trade access to the west coast and Mexico. d. New Mexico lived up to its reputation as the 'Land of Enchantment.'

The answer is "Option c"

Explanation:

In 1861, inside an effort to control the Southwest U.s country to make it accessible to a Union-holding California, the Confederacy tried to claim to be the south half of the vast New Mexicans Territory and led this same ambitious new Mexico campaign; this was why Texas was the Union but also Confederacy's critical score, given its trade and travel on the west and in Mexico.

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