Apparently the ascribed tltle, "Upright Pines" for the Muskegon exhibition was derived from a nototation on the verso that alluded to the vertical format of the canvas, rather than the obvious direction of the tree growth.
Anita M. Gilleo Trust
Artists of Michigan From The Nineteenth Century - A Sesquicentennial Exhibition Commemorating Michigan Statehood 1837 - 1987
Sweeney, J Gray, etal, Artists of Michigan from The Nineteenth Century (The Muskegon Museum of Art & The Detroit Historical Museum, 1987) .
Smithsonian Institution Research Information System (SIRIS), "Alten, Mathias Joseph 1871-1938"