Thanks to Ted Ackley on the Studio Pottery Collector's Group for identifying the >R makers mark as that of Rowantrees Pottery, Blue Hill, Maine.
I'm not sure which decade these pieces were made, and looking around online, it appears that Rowantrees Pottery have used several variations of marks over the years, some of which included the name Rowantrees, sometimes even including Blue Hill Maine, most of them have some variation of the Rowantrees Pottery >R signature makers mark..
Rowantrees Pottery opened in 1934 and was in production until 2009. Rowantrees Pottery was founded by Adelaide Pearson and her partner, Laura Paddock. Sheila Varnum, who is now in her 80's, was a Rowantrees Pottery employee of 30 years when she assumed ownership of the pottery studio in the 1970s..
According to Andrew Phelan, author of the book "Following the Brick Path, The Story of Rowantrees Pottery" , Rowantrees Pottery's products are "highly valued by collectors", yet, I don't see that claim even remotely accurate since there are many examples of Rowantrees Pottery that have been available online for quite some time and remain unsold at low prices.
There's also Rowantrees Pottery reproductions, produced by Lowell Hill Pottery, although I can't see why anyone would want reproductions when one can easily find an original.
Update: Jan. 25. 2015. I am thinning my collection and have decided to list this Rowantrees Pottery set on eBay.