Here is the letter, I came across this while researching another treasure story, I filed it away and have not done much with it as the Author is not considered reliable. I redacted the name of the creek mentioned but it is in the fifty mile mountain area.
Mr. R. Clayton
Coalville, Utah
P.O. Box 282
I should have answered your letter long ago, but I neglected it for I
have been busy. You wanted to know about caves. Many years ago Jim
Bridger, a Ute Indian and myself went down Green river, Grand and
Colorado rivers to where Virgin river empties into the Colorado
river in Nevada.
This was in the summer of 1868. We prospected all the way down
We had two Indian bullboats tied together. Where Curtis
creek empties into the Colorado, in the Orange Cliffs, we prospected
up the creek. It was in a small canyon on the east side of the
creek. The entrance was small at that time, there was lots
of brush grew in the canyon. We followed bear tracks to the cave.
We went into the cave with pine torches, but the would not burn
good so we did not explore it. It extended back into the cliff
we did not know how far, but we did not find the bear.
Where the .....................creek empties into the Colorado river,
the first big bend in the Colorado river above where this creek
comes in, we found a large cave, and explored it back for a
long ways but we never found the end. There was quite a
number of human skeletons, but the bones were very brittle, for
they had been there a long time. For there was Spanish armor
lying by the bones, and shields and flintlock guns and pistols
and one sword. The coat of arms of Spain was on all of these
dated 1730. I have wanted to go back to this cave and get these
articles but never did for the country is very mountainous and hard
to climb. The Indian would not go into this cave for he said the
evil spirits lived there.
Tom Rivington