The easiest way to find this route is to hike until the "Monolith Spire" is in view. This looks like a 70 meter tall skyward-pointed hand almost touching the canyon wall. Only the index finger of the "hand" is extended on the left side. There is no thumb and the other fingers are there only to the middle knuckle. With this image in mind, and scanning the south-facing wall on the way in on monument trail, it would be impossible to miss. From the trail, look left of the monolith spire to a huge chimney that goes from the gound to the rim of the canyon. Perhaps only 5 meters right of this is the base of Big Bertha. To approach it, walk up the slope to the climb.
Start climbing on fingers in the left-facing corner and continue up the progressively widening crack until it becomes more of a slot than crack. The beta is simple- if it gets too hard, turn around and face the other way. Repeat as many times as necessary.
To descend, rap from anchors to the left of the top of the climb, more or less at the mouth of the chimney. A 70m rope was nice. A single 60m might make it. The bad webbing on the 2 good bolts at this anchor was replaced and re-enforced (2005) - it should someday be replaced with chain, but I did not have any with me. Be prepared to work on anchors like this at any time.
A run of cams from .5" to 4" with extras in the hand-to wide range. I wished I had taken an extra #4 camalot or saved it until higher on the route.A 70M rope gets you down no problem. A 60M might require you to swing to the left to land on a ledge or perhaps fall slightly short.