SHERIDAN, Wyo. (AP) — Opponents of fluoridation say they're no longer planning to sue the city of Sheridan but aren't backing away from trying to block the addition of fluoride to the city's water supply.

Erin Adams is a member of the group Clean Water Sheridan. She says the group plans to continue gathering petition signatures asking the Sheridan City Council not to add fluoride to the water.

Sheridan was among the first U.S. cities to fluoridate its water in the early 1950s. The city abandoned the practice after a 1953 referendum opposing fluoridation.

City officials tell The Sheridan Press ( ) the 1953 vote was advisory only and can't prevent fluoridation after a hiatus of more than 60 years.

City officials have been installing fluoridation equipment at two water treatment plants.