Close Window • Print this page    Click for more of the best photojournalism: A fish "ladder," right, has been installed next to the Peirce Mill waterfall so that fish can get past the dam. Fish have been unable to make it farther upstream to lay their eggs since the dam was built in 1904. In the past three years, environmental engineers found ways around, over or through eight such obstacles that prevented fish from passing. Photo Credit: By Gerald Martineau -- The Washington Post Photo