Complex sentence: When copper ore was discovered in 1866 and mining began, the Central Pacific Railroad started a station to support the mining activity and in 1870 moved the Argenta station to Battle Mountain and established a townsite to serve the Battle Mountain copper and gold mining district.
Split into simpler sentences: When copper ore was discovered in 1866 and mining began, the Central Pacific Railroad started a station to support the mining activity. In 1870 the railroad moved the Argenta station to Battle Mountain and established a townsite to serve the Battle Mountain copper and gold mining district.