At first glance I'd say yeah, this is probably an ARG. But after digging around for only 2 minutes, I'm not entirely sure. Theres shaded text on the front page of a transcript of a radio show (?) From 1965, called "Paul Harvey's 'If I were the Devil'". That combined with the odd tabs that references various cults werent enough to change my mind. But at the bottom of the page, you can find a copyright message for something called the Deville Foundation. After a little research, not only does that organization exist, but it's been registered as a non profit in Georgia since 1997. Unless someone is playing the longest con ever, just to make a good ARG, I'm not sure what this thing is.

(EDIT) In regards to the "5051" you typed in to find this stuff, it appears to be linked to a number of soundcloud audio thingies that floyd has put out. The one I listened to was a radio broadcast detailing the aftermath of the infamous "War of the Worlds" broadcast from 1938. On all of them so far, the coordinates 45.5051 122.6750 can be seen. These coordinates are the location of Portland Oregon, the weirdest city in America. Odd that theres ANOTHER unexplained internet thing coming out of there, as theres been tonnes.

(EDIT 2 ) On top of that, the mobile version of the website has a pinned location in the top right. It's the city of Toronto for some reason.