Light.

  I harp and harp on this to students and drive myself a little batty watching for it, but LOOK at the two different photos.....everything the same except lighting.  The canyons have spectacular light on the shady side...often aided by the light bouncing from the far sunlit wall, especially late.

Early in the day.  I'd noticed these trees on a night drive out of CDM.  The light was chattery and the sun would be behind a cliff in an hour or so.

Couple of hours later.  It kept getting better until the light came off the cliff to the right of the image.

Can't say this too much.  Same subject, different lighting: completely different image.

That's a little group of Navajo kids hiking the canyon going down the road.  They had come down off the rim and were walking to a campground.  Great place for kids.

Update.  5X7 HP5 negative just out.  On the meter I use, (Pentax 1 Degree Spot), I rate it at 600.  X-tol 1:1 for 9:20 @ 68 degrees.  Looks good.