Karval is an unincorporated community and a U.S. Post Office in Lincoln County, Colorado, United States. The Karval Post Office has the ZIP Code 80823.A post office called Karval has been in operation since 1911. The community derives its name from G. K. Kravig, a pioneer settler.Karval is located at 38°44′00″N 103°32′13″W / 38.73333°N 103.53694°W / 38.73333; -103.53694.