I tried your link, but did not see the event. At a guess it is either Bentonville or Breckenridge.
I meant Tucson.
Here in Sacramento I am in and around maybe the largest hub of mountain biking in the country and maybe less than ten miles from Ventana, but there's little MTB tandem activity I've found so far. A 1600 mile round trip to Tucson is not in the cards. But I grew up riding around the Phoenix exurbs and my nostalgia gets triggered by photos of knobby tire bikes and saguaros