Sweetgrass Winery's Back River Gin is hard to get. Their website says they will ship through vinoshipper.com, but due to complicated alcohol-shipping laws that vary state by state, that option can only reach NH of the six New England states. They cannot ship to New York, either. I got my bottle at the Bow Street Market in Freeport.
Sweetgrass Winery, of Union, ME, makes a wide range of fruit wines supplemented by vanilla extract and this gin, a cranberry gin, a whiskey, a vermouth, and bitters. I have not tried any of their other products yet, but the dry vermouth was the subject of raves by the bartender at Three Tides, a restaurant in Belfast attached to the famous Marshall Wharf Brewery.
Here's something interesting: the alcohol base of the Back River Gin does not come from the usual grain mash, nor from potatoes like the Cold River Gin, nor from apples like the Karner Blue Gin; it comes from blueberries!
I really like the Back River Gin. It is simultaneously herby and floral-fruity, but not as soft as the Karner Blue. It has great complexity, with the blueberry working with the juniper to make a strong backbone that supports many flavors that come and go as it warms in the mouth. It reminds me of the hilly rugged blueberry barrens downeast near Ellsworth and Stonington.
It made an excellent Martini with Martini & Rossi Dry Vermouth and another with Dolin Dry Vermouth. With Vya it was absolutely sublime. All Martinis were made 4:1 in small glasses with no garnish.
I do not know yet how it will go in a gin and tonic. It was good in a Monkey Gland, but the gin's complexity was overwhelmed by the flavors; I would not use it in a Negroni. It makes a fabulous Aviation.
You can find an excellent review of this (and other gins) at the encyclopedic TheGinIsIn blog.