On Feb. 9, 1966 the NHL executed its first major expansion, doubling in size from six teams to 12. Today, 50 years later, four of those teams are still around. And in recognition, they each unveiled their 50th anniversary logos to be used during the 2016-17 season.

The Pittsburgh Penguins, Philadelphia Flyers, Los Angeles Kings and St. Louis Blues will each mark five decades on the ice with special commemorative logos and season-long celebrations. Here's a rundown of what we know so far.

Most notable in the Penguins' logo is the use of the classic yellow — which suggests to the full time use of the throwback jerseys next season.

Plus, the team's press release reads, "the Penguins announced that all items at PensGear stores at CONSOL Energy Center will be 50-percent off for the next five home games." Everything in Vegas gold must go, right?

The logo also includes a nod to the franchise's three Stanley Cups.

In other Pens-related news, ESPN's Scott Burnside reports Heinz Field will again host an outdoor NHL game. This time, the Penguins would host the Flyers in the Keystone State golden anniversary showdown we've all been expecting. Then the following season, the teams would face off outside again in Philadelphia.

Speaking of the Flyers, their anniversary logo plays off the keystone design that's used on their third jersey's captain patches along with a big, gold 50. Hard not to like that design.

Their plans for next season involve a new 50th anniversary jersey which was teased with the publicity photo above, featuring the anniversary shoulder patch and the classic Reebok Edge collar style. Curious to see what this one will look like as the Flyers are the only one of these teams currently wearing their original 1967 sweater design.

Speaking of which, in 50 years very little has actually changed about this team's look. That's remarkable and speaks volumes about the strength of the brand.

The Kings created their anniversary logo by toying with elements of their current primary mark. Replacing the modern crown is the classic 1960s version — in black and gold. The logo features a 50 between the years 1967 and 2017 while the entire design is outlined in gold trim.

The team will reportedly wear a "series" of throwback jerseys during the 2016-17. They'll definitely have no shortage of options in that area.

As for the logo itself, I think this may be the weakest design of the group. The silver and gold combo is just the sort of garishness one might expect out of shiny Los Angeles.

Finally, there's the Blues who went totally minimalist with their logo, proving you don't need clichéd ribbons or extraneous metallic colors to create a solid anniversary design. Just the Blue Note and a 50. Crystal clear.

Now, I say that, but of course TV networks can't help but produce flashy graphics so this version also exists in the world. Sadly.

In their press release, the Blues didn't specifically mention any throwback jerseys in the works for next season, but I'm sure they have something in the works.

By the way, three teams were in action on their 50th birthdays tonight. The Kings killed Boston, 9-2. (Ridiculous.) The Flyers lost to Anaheim, 4-1. And the Blues were just edged by Winnipeg in a shootout. The Penguins are in NYC tomorrow night.

Lastly, since I know someone will ask me to rank these four logos, it goes like this: Blues, Flyers, Penguins, Kings. What do you say?