The area of Porcelain Basin from Incline to Blue to the berm next to the Lava Pools underwent an Orion Group-style dormancy from either 1994 or 1995 until a year or two ago (from what I hear--I haven't been back to see the recovering water levels). The near lack of discharge from the upper group of Biscuit Basin since the early (or mid-?) 1990s might qualify. This old photo of Avoca and Silver Globe Springs is certainly food for thought: <a href="http://www.flickr.com/photos/darryljames_whitesheep/3927960428/in/faves-64625555@N06/">http://www.flickr.com/photos/darryljames_whitesheep/3927960428/in/faves-64625555@N06/</a> as well as this one of Jewel: <a href="http://www.flickr.com/photos/darryljames_whitesheep/3907196077/in/faves-64625555@N06/">http://www.flickr.com/photos/darryljames_whitesheep/3907196077/in/faves-64625555@N06/</a> For what it's worth, the Daisy Group dormancy of the 60s strikes me as distinct from the other examples. While the major geysers of the group did stop erupting, my understanding is that they maintained their water levels, more or less. In your other examples, as well as mine, water levels in an entire system dropped drastically and all at once without an obvious cause. David <div class="gmail_quote">On Mon, Aug 1, 2011 at 11:26 PM, JEFFREY CROSS <<a href="mailto:jeff.cross@utah.edu">jeff.cross@utah.edu</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"> I recall overhearing once that during the period of Giant Geyser's dormancy from 1959 through the gradual reactivation in the mid-1980s, wildflowers and grasses grew on the Giant platform. Is this indeed true? How many other groups of geysers have gone dormant all at once, as the Giant Group did during this period? I can think of three: Orion Group, Shoshone Geyser Basin, late 1970s and ongoing Lower Group, Heart Lake Geyser Basin, between 2008 and 2010 and ongoing Daisy Group, Upper Geyser Basin, during the 1960s and recovered in the 1970s Any other areas? I'd like to include this information in a short article that I am planning to write. It's an interesting topic, because of the distinct difference between the dormancy of an individual thermal feature and the simultaneous dormancy (I suggest the term "systemic dormancy") of a group of thermal features. Examples of the latter case seem to occur most frequently (but not exclusively, as the above examples show) as the result of geothermal energy development (ex: Beowawe, Steamboat Springs, Long Valley (?), and too many examples from New Zealand and Iceland). Examples of the former are numerous and routine. Jeff Cross jeff.cross@utah.edu_______________________________________________ Geysers mailing list <a href="mailto:Geysers@lists.wallawalla.edu">Geysers@lists.wallawalla.edu</a> <a href="https://lists.wallawalla.edu/mailman/listinfo/geysers" target="_blank">https://lists.wallawalla.edu/mailman/listinfo/geysers</a> </blockquote></div>