After the signing of the 1868 Treaty, an elderly man named Chief Munyanna settled the lake area. When asked for his name the Anglo could not spell it from the pronunciation so they renamed him Chief Mariano. The community did not have a name at the time. Chief Mariano and his scouts began construction of an earthen embankment to catch rain and melting snow runoff. The workmen used arrows, saddle blankets and rugs to excavate the silt to build the embankment. Soon after, the dam created a lake. Because Chief Mariano, mobilized the construction of the dam. The lake became known as “Mariano Lake”, and eventually, the community became known by the same name.