It's actually less than a year younger than BBBB. At least, the earliest So Cal Broncos trip I can find in my photos archive is from March 2003 (BBBBI was in June 2002). But I don't believe it has been an unbroken streak. For the first few years it was in March (with one in April, and a couple of fall trips thrown in). I'm not sure when the tradition to do it MLK weekend started. My earliest photo set from the MLK Calico trips was in 2014, but I may have missed a few before that as I went through a spell where I wasn't able to attend them all (that spell is still in effect LOL). But the move to MLK weekend seems to be about when it transitioned to its current form.