The large "dead" tree in this picture is not the Bristlecone Pine Tree. I have no really good idea how old the Bristlecone Pine Tree in this picture is; it (the small green one) is obviously alive and doing well. The tree is about six foot tall and according to text I've read it takes about 400 years to a Bristlecone Pine to hit the four foot mark.

The next thumbnail in this gallery shows a close-up of Bristlecone Pine needles; they are clumps of five individual needles joined at the base. Because of the short length of the needles I'm pretty certain the tree in the picture is a Bristlecone Pine and not a Limber Pine Tree. Limber Pines also have clumps of five needles joined at the base but they have much longer needles (2.5 to 3 inches in length) compared to those of the Bristlecone Pine (about 1 inch in length).

There is another Bristlecone Pine Tree (refer to thumbnail past the needle clump close-up) at Bryce Canyon that is estimated to be 1600 years old; there are no green pine needles on that tree. I should point out that at this point in time nobody in the park service is certain if the 1600 year old tree is dead, or still alive but dormant (it isn't unusual for Bristlecone Pine Trees to lie dormant for many years).