Until a few days ago if you asked me if beer was Vegan friendly I'd have said, "well-duh"? I mean most people know that beer is four things. Malted barley, hops, water and yeast. What vegan could have a problem with that? Well there are some technicalities that come into play.
Generally most beers made in the U.S. are Vegan friendly. Some beers like Milk Stouts and Oyster Stouts are obvious exceptions, but for the most part craft beers have no animal materials in them.
Some breweries clarify their unfiltered beers using a fining agent known as Isinglass, which are made from the swim bladders of fish. It's a clarifier that only filters out unwanted particles from the brewing process and is not present in the final beverage. These types of organic agents tend to make beers a "no-no" for people who want to stay away from from animal parts for dietary or religious reasons.
I can say confidently that most of Utah's brewers use mineral based clarifiers like Biofine Clear which is basically colloidal silicon dioxide.
Squatters just recently debuted O'Caden's Irish Red, their first "vegan friendly" beer using these new clarifiers. Pretty much all the beer they make - that is not filtered - is clarified with this process. Emigration Amber, Chasing Tail (pub only), Oatmeal Stout, Full Suspension, ESB etc.
Some of the other breweries using non organic clarifiers are the Utah Brewers Co-op and the soon to be brewing Epic Brewing. Just to mention a few. If your interested in knowing who's using what, the individual breweries will be happy to let you know.
These Clarifying processes may also apply to people who desire Kosher beers as well.
The funny thing is, there is not a vegan brewer among us. I guess they just like to please. Are we Clear?