This will be the third time I've guided Dan in a marathon. We also did a 1/2 Ironman together last year. We were tethered together on the 1.2-mile swim, rode a tandem bicycle on the 56-mile bike portion and held a tether between us on the 13.1-mile run. And we'll run the Boston Marathon together on April 20, 2015. He's in remarkable shape and always up for an endurance challenge. There's more to come!
Scott Pelley introduces the story about Dan Berlin
Dan being interviewed by Barry Petersen, one of CBS's most experienced correspondents
In this photo, I'm helping Dan cross a stream in the Grand Canyon with assistance from fellow guides Alison Qualter-Berna and Pete Kardasis