I found and signed this petition on Backcountry Pilots forum. Who knows, maybe this can help keep 91 octane around:

"If you are looking for ethanol free mogas you have probably heard of the web site www.pure-gas.org, which lists locations around the country to find sources.

The owner of the site has started a petition to send to EPA administrator Lisa Jackson, who actually has the authority to make sure ethanol free premium unleaded gasoline is available. You can sign the petition and add your comment at: http://www.thepetitionsite.com/1/keep-pure-gas/

Please sign the petition if you need ethanol free mogas for your flying. If nothing is done by the EPA or state governments in the next year all gasoline in the U.S. will be E10 because of the unintended consequences of the federal RFS mandate in EISA 2007, which ironically is not a mandatory E10 law, but is having that effect.