HELENA, Mont. — State agencies are telling people heading to Montana lakes and reservoirs this summer to watch for harmful algal blooms.

According to a press release, those blooms can put toxins in the water that may cause skin irritation, make people sick and be deadly for pets or livestock if swallowed. The release asked people to report suspected blooms on the state website.

State officials summed up the advice in a short warning.

"When in doubt, stay out," state officials said.

People should avoid drinking, swallowing or swimming in water that looks suspicious, officials said. They also said children, pets and livestock should be kept away.

The press release said blooms may show up as scum or unusual color in the water and can look a bit like spilled paint, pea soup or grass clippings. They are usually blue or green.

Officials said anyone who thinks they came into contact with a bloom should rinse off right away with tap water. In an emergency, they said people should call Poison Control at 1-800-222-1222.

The agencies said the state website includes bloom reports, advisories and a map of suspected problem areas.