See the LIFE Version of the Swimsuit Issue

Every February, in the very depths of winter, Sports Illustrated unveils its storied swimsuit issue. And when that issue comes out, the media — print, online, TV, radio, semaphore, you name it — takes notice. There are, one can state with a certain degree of confidence, several reasons for the attention that the swimsuit issue garners:

First: It seems the women are quite attractive.

Second: The bathing suits, while barely there, evidently appeal to a number of people — perhaps even to women.

Third: The swimsuit issue has a surprisingly long history — especially in the magazine world where, with a few notable exceptions, franchises come and go with dismaying rapidity. This year, in fact, marks the 50th anniversary of the swimsuit issue, which means that this particular annual media tradition has very likely been around, essentially unchanged in theory if not in practice, longer than most of the people who will enjoy the 2014 issue.

Finally: There are the women. Wait . . . perhaps we mentioned that already?

[Buy the book, Sports Illustrated Swimsuit: 50 Years of Beautiful.]

Here, in tribute to SI’s swimsuit issue, and in recognition that in its own way LIFE magazine also took pains to chronicle youthful frolics in sand and surf, LIFE.com presents a series of photos made by Co Rentmeester in California in 1970.

There’s a certain innocence about these pictures that signals, right away, that they were made long, long ago. Sure, it’s California in the post-Manson, post-Altamont years, when the California Dream was souring and the airy promises of the Sixties were fading. But even the onslaught of hard drugs and pseudo-revolutionary nihilism that subsumed much of the counterculture in the early ’70s could not entirely wipe away what had always drawn people to the Golden State. Namely, an uncomplicated joy in the pleasures of sunshine, sensuality and the illusion of eternal youth.

And if the California Dream really is just that: a dream? Well, honestly — who cares?