Muir Snowfield Professional Review and Guide
"The broad, low-angle southern apron of Mount Rainier rises from Paradise at 5,440 feet to Camp Muir at 10,060 feet. Early season tours (October to November) offer the best combination of snow conditions, weather, and entertainment value on the Muir Snowfield.
Navigation skills (and the requisite equipment) are required for this tour; whiteouts occur frequently, and the descent takes place on a broad, curving ridge with cliffs on either side. Keep a log, mental or otherwise, so you can find your way down in fog. Difficulties: Moderate avalanche potential; routefinding required; permit / fee area."