After being elected as Justice of Peace in Trinidad, Barela was named County Assessor in 1870. While serving in this new position, in 1871 by popular vote, Barela was also elected representative to the Territorial Legislature. While fulfilling his public offices, Barela also found success with his several businesses on the side, and enjoyed spending time with his wife and young daughters in the early 1870s. In 1875, Casimiro Barela helped to write the Colorado State Constitution, and he guaranteed its publication in English, Spanish, and German. While fighting for the publication in multiple languages, Barela stated, "You may say that ignorance of the law does not excuse the breaking of it. I say it is the only excuse." Casimiro Barela served as a Delegate to the 1880 Democratic National Convention in Cincinnati, Ohio and the 1888 Democratic National Convention in St, Louis, Missouri. In addition to his service as County Assessor and Justice of Peace, Casimiro also served as County Sheriff for Las Animas, ran a blacksmith and supply shop, and was a postmaster.