Morning Geyser is the largest geyser in the Fountain area and one of the largest geysers in the world. Unfortunately, it is seldom active.
Active periods in the past 30 years included 1973, 1978, 1981-1982, 1991, and 1994. It rejuvenated in June 2012, with occasional reports of activity through now (early May, 2013). The current activity has included two reports of dual eruptions with Fountain--one on October 30, 2012 and the other on May 3, 2013. (The only other known dual eruptions occurred August 20, 1959 and July 4 and 5, 1991, and August 9, 28, and 29, 1991.)
When active Morning can erupt as often as every 4 hours, although intervals may also be several days during active periods. It can erupt to 200 feet high and 100 feet wide. Durations of eruptions vary from 10 minutes to over an hour.