Born in North Madison, Connecticut, he was brought by his parents to Hendricks County, Indiana, in 1860. In 1862 the family moved to Putnam County, Indiana, where Blatchley received his elementary education. He entered Indiana University in March 1883, where he majored in science (botany, zoology, and geology), and graduated in 1887. From 1887-1894 he taught science in Wiley High School of Terre Haute.
In 1894 he was elected State Geologist of Indiana on the Republican ticket, a position which he held until 1911. From 1913 until his death he wintered in Dunedin, Florida, and spent his summers in Indiana, writing and collecting scientific specimens.
From the description of Papers, 1883-1940. (Indiana University). WorldCat record id: 36935110
