Gliders in the Grand Canyon

d&tm writes:

Is that a recent rule? I vividly remember my trip to the Grand Canyon in
1985 It was our honeymoon and I havent been able to get back since.
We took a 1 hour flight in a Twin Otter of Grand Canyon Airlines. It went
way down into canyon, and it was quite specatacular looking out the window
to see a rock wall.

The rules are post-1985. Today you cannot go below 14,500 feet MSL, except in
designated corridors, all of which have a minimum floor of 10,5000 feet MSL.

In other words, you can no longer go down into the canyon, except for take-off
and landing there.