Definition of "bypath"

Having gone to Chiang Chou from Chü-wo by the northern route through Hou-ma, we returned over a bypath through mountains in the south which has been gradually elevated from the Fêng River valley by loess deposit.

1927, Chi Li, “Archaeological Survey of the Fêng River Valley, Southern Shansi, China”, in Explorations and Field-work of the Smithsonian Institution in 1926 (Smithsonian Miscellaneous Collections)‎, volume 78, number 7, Washington, D.C.: Smithsonian Institution, page 129

During these days, the boy rode Sir Mortimer abroad in many directions until he knew every bypath within a radius of fifty miles of Torn. Sometimes the old man accompanied him, but more often he rode alone.

1927, Edgar Rice Burrows, The Outlaw of Torn‎, HTML edition, The Gutenberg Project, published 2008