Paul,
At Blackhawk, it was as simple as Rod fitting the holes to the ground. All 18 happened to add up to about 6,700 yards. There was absolutely no discussion about total length throughout development of the course, which is probably abnormal these days as well. The inherent terrain provided for a good mix of short, medium, long holes.
Unfortunately, I don't have any good photos of the course right now. I, personally, haven't been back since it officially opened for play in July. However, I'll get in touch with the superintendent, Duane Sharpe, who has taken a large number of photos this season. I'll ask him to post a few good ones for you, when he has a chance.
As for the bunkers, yeah, the general theme is rugged. But there's a good mix of flashed sand and grass faces throughout the course. There are small bunkers, like the pot guarding a front right hole at 10, and very large ones too, like the 'blow outs' in the hillside short left of 18 green. Variety, variety, variety!