It depends on what you mean by "end." If you're talking counterculture -- broadly defined -- I think this is more of a journalistic fairytale that overexaggerates Manson than anything else. Many of the key works of art, culture, and styles of political practice that we associate with the "1960s" persisted into the early 1970s, whether we are talking about feminism, sexual liberation, gay rights, or Third Worldism.

If I were to date an "end" to the 1960s, it'd be 1973, when the institutional underpinnings of post World War II political and economic stability started to fray rapidly: OPEC oil crisis, the end of Bretton-Woods, economic stagnation, the onset of global competition to the United States, inflation. The "1960s" occurred partially out of a reaction to alienation caused by economic affluence., In the 1970s, that affluence was increasingly scarce.