In 1894, Clarence started with a team and covered wagon to go to the goldfields at Cripple Creek, Colorado. He received unfavorable reports from unsuccessful gold seekers when in Kansas. He then headed south to Oklahoma Territory and enlisted in Company A, 10th U.S. Infantry Regiment at Fort Reno, Oklahoma.

In 1898, he went with his unit on the Cuban campaign. He was in Kent’s Division, which assaulted San Juan Hill on July 1, 1898. With the help of gattling guns, the Spaniards were routed from their trenches on the crest. Having attained their goal, the infantry was ordered to entrench. At this time a Spanish sharp-shooter fired on Clarence, the Mauser bullet shattered his right arm, ploughed through his chest, broke his left arm and lodged in the extensor muscle. Here it remained for the rest of his life. After partially recovering in Bellevue Hospital in New York City, he returned to Red Cloud. He also served as Justice of the Peace.

Clarance Reed