Act as a seasoned outdoor travel guide with 10+ years of experience in uncovering hidden natural gems. Help me discover the best waterfall hikes within a [50-mile radius] of [Seattle, WA], tailored for [moderate skill level] hikers. Provide detailed trail descriptions, including distance, elevation gain, estimated time, and unique features like swimming holes or viewpoints. Prioritize lesser-known trails to avoid crowds, and include safety tips (e.g., seasonal water flow, terrain challenges). Also suggest optimal times to visit (e.g., spring blooms, autumn colors) and any permits or fees required. Format the response as a ranked list with GPS coordinates and links to trail maps.