Updated

Good genes? Bountiful bank accounts? Plain old fashioned hard work?

Whatever the reason, decades after the world’s “supermodel brat pack” started strutting the runways, the gals are sexier than ever and still making the big bucks, with most well into their 40s.

Let's take a look.

At the age of 45, Cindy Crawford adorned the cover (and showed off her legs) for the May 2011 issue of Vogue Mexico.

Young-un Kate Moss, clocking in at 37 years, is smoldering nude on the May cover of Brazilian Vogue.

More On This...

Linda Evangelista, 45, is the face of fashion giant Talbots, in addition to her lucrative contracts for L’Oreal and Prada.

Christy Turlington, 42, works for Maybelline, Bally, Bottega Veneta and Louis Vuitton.

And 40-year-old Naomi Campbell still hits headlines for her diva-esque bad behavior while regularly walking the runway for top fashion houses in addition to appearing on the June cover of Vogue Japan.

So what makes their appeal so everlasting?

“These women have a star power and recognition that tends to be lacking for most runway models these days. They came up in what is recognized as the high point of the ‘supermodel era’ and still command enormous recognition,” L.A.-based fashion and business expert Anne Riley-Katz told FOX411’s Pop Tarts column. “It also doesn’t hurt that they remain unquestionably beautiful two decades later.”

Associated Press entertainment and pop culture expert Natalie Rotman says there is a certain cultural intrigue with watching these women subtly and gracefully age.

“Cindy Crawford, Naomi Campbell and others have learned from their predecessors like Christy Brinkley and Iman, the importance of building a brand and taking care of their skin to be appealing in a vain market,” Rotman said. “And any icon in a field, whether it be Kate Moss in modeling, Sophia Loren in acting or Madonna in singing, will always continue to be a hot commodity. Society is obsessed with aging, so therefore what can be more fascinating than looking at the most beautiful women in the world and how they age?”

It’s also interesting to note that the era of the 90s supermodel was an era in which the fashion industry embraced female curves as opposed to demanding dangerously thin bodies. Years later, most of these ladies are fortunate enough to still have their health and an unmistakable glow.

“I certainly felt pressure to fit the clothes and to stay thin but when I was modeling we were allowed to have normal healthy bodies. It wasn't like it is today,” Crawford told us at a recent event in Malibu. “And even the thin models of my time like Kate Moss, like, that's just her body. She's naturally super thin. I mean I saw her eat burgers it's not like she was starving herself or anything like that.”

And while Crawford admitted she isn’t exactly psyched about continuing down the passage of time, she understands the business value that stems from getting older – and the business value of keeping her fabulous figure.

“I don't think aging is fun for anyone and watching those changes, but that's why it's important to have balance in your life and other things that you're focused on. But at the same time it's been a great vehicle for me to have a career and lifestyle,” she said, adding that keeps taunt and trim by exercising around three times per week with such activities as hiking, yoga, weights and pool classes.

And let’s not forget now that this select group of stunning ladies has also proven that they’re more than just pretty faces and flawless figures.

“A great number of supermodels from the 80s and 90s have been highly successful in parlaying that segment of their career into other enterprises, from beauty products, home goods, TV shows, jewelry or clothing lines, which makes their names part of a larger brand presence,” Riley-Katz explained. “That transcends the ‘age myth’ through a formidable business presence, and gives much longer run as public figures and in some cases, as entrepreneurs.”

For example, in 2005, Crawford created a line of beauty products with Dr. Jean-Louis Sebagh called Meaningful Beauty for Guthy-Renker, and that same year introduced a line of furniture under the "Cindy Crawford Home Collection" name. She also has a furniture line with Raymour & Flanigan and in late 2009 launched another home goods line with J. C. Penney.

Model-turned-yoga lover Christy Turlington founded two successful lifestyle brands; SUNDÃRI, an Ayurvedic skincare line and nuala, a yoga inspired apparel and accessories line, authored a book and directed the 2008 documentary about post abortion healthcare, “No Woman No Cry.”

This year Claudia Schiffer launched her own cashmere collection, and model mogul Elle Macpherson is continuing to expand her underwear collection “Elle Macpherson Intimates.”

One expert says this generation of supermodels will never be matched.

“The age of the ‘supermodel’ is over and has been replaced with ‘celebrity.’ It is about celebrity, branding, licensing and franchising,” added Marie P. Anderson, fashion and beauty director at Agency Galatea – Model & Artist Management. “These (the original supermodels) came at a time when models were allowed to have personalities. This elevated the nameless gorgeous faces into celebrity status, giving them a foundation to change the rules of the industry worldwide.”

Deidre Behar contributed to this report.