Rosalia Battle Days is an annual town celebration held the first weekend in June. it features a parade, dance, food events, rodeo, fun run, and other entertainment. Battle Days was started in 1970 with the help of the Odd Fellows Lodge.
The name refers to the Indian War of 1858 in which Colonel Edward Steptoe led his troops to one of the territories worst defeats at a site on the east side of Rosalia that is presently marked by a monument.
Battle Days was started to raise money for a museum and to help draw people into town after a new highway was built that bypassed Rosalia. Enough money was earned in that time to build the museum in City Hall.