By Ginger Gibson CASPER, Wyo. (Reuters) - Republican U.S. presidential hopeful Ted Cruz won all 14 delegates at stake on Saturday in Wyoming, besting rival Donald Trump, who made little effort to win the rural state, and further narrowing the gap in the race for the party's nomination. Cruz is trying to prevent Trump from obtaining the 1,237 delegates needed to secure the Republican nomination at the July convention in Cleveland. By continuing to rack up small wins, Cruz is gaining ground on the New York real estate mogul, who has thus far failed to shift his focus on the local-level campaigning necessary to win delegates.