That's a hole in the clouds, but it is indeed strange.
They say it's because of warm and cold air coming together, but it only happens in that region....
Here another tunnel-link:
paranormal.about.com...
GRAND CANYON MYSTERY
The April 5, 1909 edition of The Phoenix Gazette carried a story entitled "Explorations in Grand Canyon." According to the article, a man named G.E.
Kinkaid made an astonishing discovery while on an expedition, sponsored by the Smithsonian Institute, in the Grand Canyon. Among his findings:
A mammoth chamber about 1,480 feet underground from which radiates dozens of passageways "like the spokes of a wheel."
Several hundred rooms, some of which contain artifacts such as weapons and copper instruments of a kind that have never been known to be native to the
Americas.
A crypt containing mummies - all adult males - wrapped in a bark fabric.
A shrine containing a Buddha-like idol sitting cross-legged with a lotus flower in each hand.
Stone tablets on which are carved mysterious Egyptian-like hieroglyphics.
The article also mentions a legend of the Hopi Indians that says their ancestors once lived in an underworld in the Grand Canyon.
CRUMF BURIAL CAVE
In 1892, Frank Burns of the U.S. Geological Survey reported that he found strange coffins in the Crunf Cave along the southern branch of the Warrior
River in Murphy's Valley, Alabama. The wooden coffins appeared to be hollowed out by fire, then chiseled with stone or copper tools. Each coffin was
7.5 feet long, 14 to 18 inches wide, and 6 to 7 inches deep. The lids were open on each empty coffin. The specimens were sent to the Smithsonian,
which suggested the coffins might actually be troughs. In any case, the museum lost the artifacts.
TUNNEL NETWORK UNDER CALIFORNIA
According to an article entitled "California Floats On Ocean?" in the Fall 1985 edition of Search magazine, a high-ranking but unnamed Naval officer
told of the discovery of a huge network of tunnels under portions of the west coast of the U.S. He said that U.S. nuclear submarines had explored some
of these tunnels, which are accessible just off the continental shelf, and had followed them inland for several hundred miles. Here are more
highlights of this incredible claim:
What is being passed off as the San Andreas Fault are actually large, unsupported chambers that are in the process of collapsing.
A well-known U.S. Nuclear submarine lost its way in one of the passages and was never heard from again. (Two U.S. nuclear submarines have disappeared
under mysterious circumstances - the U.S.S. Thresher and the U.S.S. Scorpion.)
Some of California is actually floating on the ocean. When oil companies began pumping oil from beneath the city of Long Beach, it began to sink - up
to 26 feet before the pumping was stopped.