The legend of Saint Urho was the invention of a Finnish American named Richard Mattson, who worked at Ketola's Department Store in Virginia, Minnesota in the spring of 1956.

According to the original "Ode to St. Urho" written by Gene McCavic and Richard Mattson, St. Urho was supposed to have cast "tose 'Rogs" (those frogs) out of Finland by the power of his loud voice, which he obtained by drinking "feelia sour" (sour whole milk) and eating "kala mojakka" (fish soup).

[7][5] Another version of the modern celebration of St. Urho's Day is that it was created by Kenneth Brist of Chippewa Falls, Wisconsin.

Brist, a high school teacher, was teaching in the Upper Peninsula of Michigan in the early to mid-1950s in an area largely populated by people of Finnish heritage.

He reely tolt tose pugs of kreen Braffest Finn I effer seen Some celebrate for St. Pat unt hiss nakes Putt Urho poyka kot what it takes.

He really told those bugs of green Bravest Finn I ever seen Some celebrate for St. Pat and his snakes But Urho poika (boy) got what it takes

He got strong and tall from viili sour And ate kalamojakka (fish soup) every hour That's why that guy could chase those beetles What grew as thick as jack pine needles

[12] There are St. Urho fan clubs in Canada and Finland as well as the U.S., and the festival is celebrated on March 16 in many American and Canadian communities with Finnish roots.

[15] Thunder Bay, Ontario, Canada, just northeast of Minnesota, is another location where St. Urho's Day is joyfully celebrated on the weekend nearest to March 16.

At the University of Turku students studying Folkloristics, Comparative Religion and Ethnology have organized a St. Urho's Day play yearly since 1987.