Environmental Life Force (ELF), also known as the Original ELF, was the first radical environmental group in 1977 to use explosive and incendiary devices in defense of the environment.
- Main article: Earth liberation
The name was founded by John Hanna who was the only member of the group to be arrested and convicted for the use of explosives on federal property. The ELF conducted armed actions in northern California and Oregon and disbanded in 1978 following Hanna's arrest for placing incendiary devices on seven crop-dusters at the Salinas, California airport on May Day, 1977.
They said that "warfare" designed pesticides were being used on domestic crops, specifically a chemical banned after it's extensive use in Vietnam. A communique to The Independent later provided the group with a frontpage story. They also called for above-ground organisations to initiate a boycott of sprayed food and for the public to criticise the process, with the following claim that: 
There was also an article published in Open Road in August 1977 featuring the bombing at a paper publishing company in Oregon City. The target was again a company who the ELF claimed were responsible for using a dangerous chemical called Tordon for aerial spraying, used as part of a program in Vietnam and responsible for causing cancer and birth defects.
- Main article: Earth Liberation Front
Several years later, the ELF acronym resurfaced, representing another eco-guerilla entity with similar philosophies, the Earth Liberation Front. There is no link between the two groups and John Hanna no longer advocates the tactics or either group.
Although not much is known about the early ELF activists, because of their efforts to remain anonymous, John Hanna, who claims to have founded the movement along with other individuals, talks of how he used explosives against a target:
Unlike his former years, he no longer advocates militancy, although does not denounce it, only denouncing militancy that leads to violence. He instead promotes the adoption of legal measures, commenting: "I accomplished more for the environmental cause through my research organization and its spin-offs than I ever did as an eco-guerilla." 
-  Q&A with Original ELF founder, John Hanna
- Environmental Life Force
- ELF declares 'war' on pesticides,, Independent, May 20th 1977, Santa Cruz, C.A.
- ELF Guerrillas Fight Ecoside, Open Road, vol #4, Aug. 1977, Vancouver, B.C.
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