Warm clothing should be worn, and one should be prepared for sudden
changes of temperature common at an altitude of 7,500 feet. Men should
have medium weight overcoats and sweaters, and women should have coats
or sweaters. Slacks or riding breeches are recommended for both men and
women. Stout shoes should be worn as they are most comfortable and best
suited for walking about the geysers, terraces and other formations.
Tinted glasses, serviceable gloves and field glasses will be found
useful.