San Francisco: Louis Roesch Co., Printers, . 1st printing (presumed). Broadside, 12 printed lines. 8-7/8" x 5-7/8". Now housed in an archival mylar sleeve. Age-toning. Small hole in upper left [just touch the top of the 'S' in 'Sutro']. Very Good. Item #46725
"On March 14, 1896, the Sutro Baths were opened to the public as the world's largest indoor swimming pool establishment. The baths were built on the western side of San Francisco by wealthy entrepreneur and former mayor of San Francisco [1894 – 1896], Adolph Sutro." [Wiki]
Here, the Baths hosted the event, which pitted entrants from "Nevada, Georgia, Tennessee, Montana and Washington Volunteers."
From an advert in the San Francisco Call, Volume 84, Number 26, we find this event occured in 1898.