Beginning Friday, 2,000 volunteers will scour 300 kilometers of river pathways in Calgary, anticipating the collection of thousands of kilograms of garbage. This annual cleanup effort, sparked by the discovery of a mattress in the Elbow River by 12-year-old Sandra Crawford in 1967, has evolved to address modern challenges such as encampments with potential hazards like drugs and weapons. Volunteers are equipped with special tools and knowledge to handle any dangers encountered, such as needles, which are flagged and reported to Alpha House for safe removal.