U.S. state flag consisting of a dark blue field (background) with the name of the state in yellow above the state seal.

In 1865 the provisional legislature adopted a seal for public business, and that same design is used by the state today. It includes a representation of the Rocky Mountains, which are fundamental to the state's topography and to its name, a derivation of the Latin montana (“mountainous”). The seal also depicts a river and forests, recalling Montana's vast stretches of natural beauty and its wealth in forestry and agriculture. Central to the design is Great Falls, a distinctive landmark that has become a tourist attraction. The plow and crossed pick and shovel symbolize agriculture and the mining industry; the latter is also referred to in the state motto, “Oro y plata” (“Gold and silver”), which appears on a ribbon in the seal. The state flag was based on the flag of the First Montana infantry regiment in the Spanish-American War (1898); the original design was dark blue with the state seal (minus its encircling inscription) in the centre. The infantry flag had lost its fringe at the fly end, so the law specified that the official state flag should be decorated with fringe at the top and bottom edges only. The flag was adopted in 1905, but many other states adopted similar designs, and the flag became less easily distinguishable. In 1981 the legislature modified the design by adding the word “Montana” above the seal.