Cristina S.wrote a review of SmartWool Trellis Kneehigh Sock - Women's on December 1, 2011
I was excited to receive these but noticed they had a bit of a scratchy feel to them. I checked the packaging and the contents listed are:
79% Wool (no mention of Merino)
I'll give them a try since the packaging says they can be returned if they "don't perform to your satisfaction" but thought others with sensitivities should be aware and save them the hassle of a return.
In defense of Back Country, the Smartwool site also has them advertised as Merino wool.
I do like that they are made in the USA, although of imported yarn.