If ever the phrase “You don’t know what you’ve got ‘til it’s gone” applied to an addictive TV show, it would be for “Mad Men.” After 17 months without the style-centric, emotionally conflicted cast of the period TV drama, “Mad Men” returned this week with quite a few new looks for its ladies, as well as some tried-and-true familiar ones, as the coworkers and wives of Sterling Draper Cooper Price are catapulted into a new era: the late 1960s.

So how have the hair styles of the female characters of “Mad Men” adapted to the new year, 1966, and all of the radical changes in style that came with it? Let’s take a look.

Joan Harris

Who says you can’t still have luscious hair after having kids? The lone redhead of the “Mad Men” cast might be creating some serious complexes for women who have recently given birth after debuting on the show with a new baby and the same rockin’ ruby locks she’s come to be known for. We saw Joan with her hair down, a rarity, in what was supposed to be a relaxed, maybe even messy look for the office manager at the beginning of the episode. But, truth be told, her soft curls and half-updo still managed to look sexy in an undone way. Later, her signature updo debuted during her return to the office, just as flawless as ever. Think new working mom Joan will experiment with some new styles this season?

Peggy Olsen
Not exactly the trendiest lady among the Mad Men, Peggy can always be counted on to represent the more traditional, classic look of the rare 1960s working woman. Though she did experiment with major mane changes in the past—sweeping her distracting, curled-under fringe and letting down her childish ponytail a few seasons ago, then chopping most of it off last season in favor of a more grown-up, though slightly uptight, bouffant with flipped ends—it doesn’t look like Peggy will be making any drastic updates to her style to reflect the new era. It does seem, however, that she’s finally figured out how to style her current one, which looked sleek, refined and actually a bit flirty (at Don Draper’s party) throughout the premiere.

Megan Draper

Spoiler alert: Don Draper has a new wife, and she’s an obscenely trendy young thing. Her polka dot blouses and chiffon minidresses aside, French-Canadian Megan rides her wonderfully exotic French genes all the way to the bank, with her naturally deep chocolate mane cut into a very mod 1960s bob. Previews with the “Mad Men” actors show that Megan eventually wears an eerily Betty Draper-esque slicked back style later in the season, but for now, we’re enjoying the exuberant and youthful playfulness that her slightly kinky bob brings to her character.

Trudy Campbell

We can tell the late ’60s are going to be very good to Trudy Campbell. Adoring wife to Pete and a new mother, Trudy always exemplified attention to trends and a socialite fashion sense on the show, but the few glimpses we got of her in the two-hour premiere showed that she had a funky side underneath the girdles and tweed all along. We were floored by the intricate twists and depth in the updo she wore to Don Draper’s party, paired with a bright printed dress.

Jane Sterling

As far as hair styles on the show go, the former secretary’s sky-high updos with impossibly sleek hair in the front were always front runners. She always seemed to represent sheer elegance and class—attitude aside—and that hasn’t changed in the new season. But Jane, married to the silver fox Roger Sterling on the show, manages to also embracing the funky, mod styles of the late ’60s while staying true to her personal style, with this truly vintage maxi dress and another sky-high updo, pulled back this time and with just a slight shift to the left side of her head.

Betty Draper

The premiere seemed to be missing somebody, right? Aside from a quick mention of “Morticia” by Don, the former Mrs. Draper was nowhere to be found in the two-hour premiere. But if this cast photo seen on AMC’s website is any indication, it looks like we’ll be getting our blonde ice queen and her no-nonsense hairstyles back, just as we remembered them.

Which 1960s styles are you dying to see on the ladies of "Mad Men" this season? Let us know on our Facebook page at facebook.com/modernsalon.