In order to fully appreciate the bristlecone pines, I think it's wise to be able to identify the other two major needled trees on the trail: the Englemann spruce and the limber pine.
The Englemann spruce, seen below, is a typical spruce tree with short, sharp needles. [Remember: square, sharp spruce and flat, friendly fir - when needing to tell spruce trees from fir trees - with the square v. flat being the respective cross-section of the spruce and fir needles, and the sharp v. friendly referring to the ouch-factor of the sharp spruce needles and the non-ouch-factor of the not-sharp fir needles.] The spruce trees had tons of cones on them.
The limber pine, a pine tree that supposedly can easily be confused for the bristlecone pine, is a pine tree with needles in packs of five, and the needles being about 1.5 to 3 inches long. Seen below, its needles are concentrated in little clumps near the ends of branches. Cones are different between the two pine trees, but I'll not get into that.
Bristlecone pines also have needles in packets of five, with the needles being about 1 inch long (possibly overlapping in length occasionally with the length of the limber pine's needles). The bristlecone needles have a distinctive look, however, growing around a branch in such a way that you will think you are looking at a million green bottle brushes. All the photos below are of the bristlecone pine.
Most of the trees in the grove are old, very old (the oldest known one that was cut down to count the tree rings was 4,900 years old in 1964 - see the story of "Prometheus" on this page).
MOH and I did, however, see some younger trees than the ones I took photos of, trees with thinner, straighter trunks. Many of the oldest trees in the grove are only alive on some branches. Other groves in the park have taller, more rapidly growing trees where soils are developed on more favorable limestone rather than less favorable quartzite.Above, bark and needles of the bristlecone pine up close; below, some nicely shaped branches.
The grove of bristlecone pines is growing on a glacial morraine composed of Prospect Mountain Quartzite, all blocky and angular and hard to walk on.
Looking back down the U-shaped glacial valley from the morraine above the bristlecone grove, you can get a great view of the grove itself, the lumpy, disorganized morraine, and the northern Snake Range decollement or detachment fault in the far distance. Most of the trees in the center of the photo in the mid-distance are bristlecone pines. The trees on the left side of the photo are spruce trees.
It was a great day for a hike!