Frogs are among the most sensitive animals to environmental change. Known as bio-indicators, these canaries in the coal-mine as it were, have suffered from the impacts of city and farming expansion in South East Queensland. With the removal of vegetation along the previously-crystal clear waters of our lowland streams, surface run-off of loose soil and pollutants has increased, clogging and contaminating their waterways. However, in the Gold Coast hinterland, a network of local citizen scientists are making their mark in a profound effort to document and map what remains. This is the story of the Cascade Tree-frog.