Written By: Ben Cosgrove

The Internet’s a funny thing—or a funny place, or whatever it is—where the most basic assumptions are, quite often, turned neatly inside out. For example: Most people might reasonably suppose that a huge amount of information about a 12-year-old girl once celebrated as the “world’s strongest seventh-grader” must surely exist all over the Web. Right?

But LIFE.com’s research failed to find anything but the most cursory details about April Atkins — a cute, perpetually grinning pre-teen who, for one brief, bonkers moment in the mid-1950s, routinely blew minds at California’s famed Muscle Beach by performing utterly improbable feats of strength.

In fact, it seems that there’s very little information out there about this extraordinary human being…

The photographs in this gallery, for example, made in 1954 by LIFE’s Loomis Dean, never even ran in the magazine. But there was a time back in the day when 79-pound April Atkins of Pacific Palisades, Calif., most definitely had her moment in the sand and the sun.

Liz Ronk edited this gallery for LIFE.com. Follow her on Twitter @lizabethronk.

April Atkins Muscle Beach Girl

April Atkins, “the world’s strongest seventh-grader,” Muscle Beach, Calif., 1954.

Loomis Dean The LIFE Picture Collection/Shutterstock

April Atkins Muscle Beach Girl

April Atkins, “the world’s strongest seventh-grader,” Muscle Beach, Calif., 1954.

Loomis Dean The LIFE Picture Collection/Shutterstock

April Atkins Muscle Beach Girl

April Atkins, “the world’s strongest seventh-grader,” Muscle Beach, Calif., 1954.

Loomis Dean The LIFE Picture Collection/Shutterstock

April Atkins Muscle Beach Girl

April Atkins, “the world’s strongest seventh-grader,” Muscle Beach, Calif., 1954.

Loomis Dean The LIFE Picture Collection/Shutterstock

April Atkins Muscle Beach Girl

April Atkins, “the world’s strongest seventh-grader,” Muscle Beach, Calif., 1954.

Loomis Dean The LIFE Picture Collection/Shutterstock

April Atkins Muscle Beach Girl

April Atkins, “the world’s strongest seventh-grader,” Muscle Beach, Calif., 1954.

Loomis Dean The LIFE Picture Collection/Shutterstock

April Atkins Muscle Beach Girl

April Atkins, “the world’s strongest seventh-grader,” Muscle Beach, Calif., 1954.

Loomis Dean The LIFE Picture Collection/Shutterstock

April Atkins Muscle Beach Girl

April Atkins, “the world’s strongest seventh-grader,” Muscle Beach, Calif., 1954.

Loomis Dean The LIFE Picture Collection/Shutterstock

April Atkins Muscle Beach Girl

April Atkins, “the world’s strongest seventh-grader,” Muscle Beach, Calif., 1954.

Loomis Dean The LIFE Picture Collection/Shutterstock

April Atkins Muscle Beach Girl

April Atkins, “the world’s strongest seventh-grader,” Muscle Beach, Calif., 1954.

Loomis Dean The LIFE Picture Collection/Shutterstock

April Atkins Muscle Beach Girl

April Atkins, “the world’s strongest seventh-grader,” Muscle Beach, Calif., 1954.

Loomis Dean The LIFE Picture Collection/Shutterstock

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