Nice covers for Michigan Conservation

Some time ago I picked up from the university library's remainder shelf several issues of a magazine called Michigan Conservation that was (or maybe still is) published by the Michigan Department of Conservartion. The contents hold no interest to me, but the covers are pretty nice. The artist signs him- or herself "Schafer" in all of the covers, but I can't seem to find any info on him or her. I'll be sending these to a friend of mine who collects cover illustrations.

First, some scans. The first one is from March, 1952, and the second one is from the same year's May. There's a previous owner's stamp on the covers. T. H. Järvi was presumably a professor of some kind and donated these mags to the library (and then they discarded them - what unthankful bastards!).