For information: the rotax 912iS operators manual stipulates 92 oct. minimum.
There are 4 listed airports in Wa. that offer MOGAS (92 oct no ethanol). The fuel tanks used in the SS7 are made from material which is resistant to ethanol.
I believe (????) they can be identified by having serial numbers etched into the inboard face. The fuel at my home airport (KOKH) has mogas however, the supplier also has the same fuel available at two of their auto fuel stations in the area which carry all three grades of no ehtanol.