Very interesting point, inselpeter. May depend on whether the phrase "in the sticks" originated before, or after, about 1860.
Until about the late 1850's, settlement of the midwest was largely confined to areas near rivers. On reason was that rivers provided transportation -- but a larger reason was that these were the more forested areas, with wood available to build houses, barns, fences, and so forth. After the late 1850's, the railroad network had developed widely enough to import lumber to much of the prairies, making settlement feasible there.
Edit: For anyone interested in the history and economic forces fueling Chicago's explosive growth during about 1850-1900, when it was easily the world's fastest-growing major city, I highly recommend Nature's Metropolis: Chicago and the Great West, by William Cronon. The chapters on the grain, lumber and meat-packing industries are particularly readable, thoughtful and informative. The author has stunning scholarly credentials (Rhodes scholar; MacArthur fellow), and the book won prizes in the field of historical writing.
