| Note: | - probable date - no time noted - RoND 1955 May – In the Norris Geyser Basin the Black Growler Steam Vent is exceedingly hot with a record temperature of 224°F. being taken there on May 7. On May 12 another temperature reading made at this site recorded only a temperature of 212°F. The steam vent is creating a much greater roar than for the past several years. In the Norris Geyser Basin there have been a number of pronounced changes occur and accompanying these is the development of two large mud caldrons on the southwest side of the main trail in the Basin, the change in character of the Coloidal [sic] Pools from a boiling, turbid pool to an eruptive geyser and the greatly increased activity in the Fireball Geyser with eruptions reaching an estimated height of 30 to 40 feet. |
