ca 1880-1900 landscape - N California School - Initialed but unknown, illegible

Unknown - Illegible (initialed ? lower left)River Landscape late 19th century/early 20thoil on board4 1/8” x 5 1/8”7 3/8” x 8 3/8” original frame, under glass Absolutely exquisite river or stream landscape on board from late 19th century (very early 20th latest) still in it’s original frame and glass. This is a beautiful work, perhaps done as a study for something larger. Brushstrokes are so fluid and deftly done that it is clearly by an accomplished artist. Comes from a long held (~40 years) Northern California collection and is now looking for a new home where it can be appreciated and cherished as it clearly has been. Shows the influence of tonalism, Barbizon, and early impressionism, all of which characterized the northern California school during this period. There were a number of well-known artists of this period including Thaddeus Welch, Charles Dorman Robinson, William Keith, Raymond Yelland all of whom captured the beauty of the N. CA landscape including Yosemite and surrounding areas. The work shows influences from them all however the artist remains elusive to me. While it is not dated, it appears to be initialed in lower left. R? K? N? H? M? Could me more than one letter but it's not clear so I will have to let you decide. Remarkably, the work appears to have been under glass and undisturbed it’s entire life as it is in pristine condition. The frame has a few minor nicks and blemishes as would be expected but still presents beautifully. It even retains the original wavy glass. While I have taken the board out of the frame to show the colors and condition (see pics), I have not removed the glass as accessing it would require disassembling the frame. Please see my pics. Forgive the inevitable glass reflections. Overall this might benefit from some museum glass but given this is in original condition, I have chosen to leave it as-is. She's a little bit of a mystery but regardless of who the artist was (it may benefit from some research), this is a gem of a piece, something very special that will bring years of enjoyment to the lucky person who takes this home. Painting will be carefully packaged and shipped, with insurance and signature verification, either UPS, Fed Ex, USPS depending upon location. Please ask if any questions and be sure to check out my other listings.