Lyric discussion by RogerRyan 

Cover art for Stacked Crooked lyrics by New Pornographers, The

"Altamont" Speedway was the location of the infamous Rolling Stones concert in '69 where an audience member was knifed to death by a member of the Hell's Angels (who were hired by the Stones as security) - it was suggested the audience member was holding a handgun. The event has long been associated with the end of the 60s love and peace era.

I suspect Carl is using the phrase "private Altamont" to refer to a personal "end-of-an-era" moment.