boondocks (n.) Look up boondocks at Dictionary.com
1910s, from Tagalog bundok "mountain." Adopted by occupying American soldiers in the Philippines for "remote and wild place." Reinforced or re-adopted during World War II. Hence, also boondockers "shoes suited for rough terrain," originally (1944) U.S. services slang word for field boots.
boonies (n.) Look up boonies at Dictionary.com
colloquial shortening of boondocks; by 1964, originally among U.S. troops in Vietnam War (in reference to the rural areas of the country, as opposed to Saigon).