There is a story that old miners in the Sierra would use the sap from Ponderosa to make turpentine which they used for lighting(?) I suppose. When they moved higher into the mountains a few of them got a nasty surprise when they couldn't tell the difference between the Ponderosa and the Jefferey pines. Turpentine has to be distilled apparently and the sap of a Jefferey contains heptane which is highly flammable - the result of their efforts was that they got an exploded still when they tried to make turpentine. These guys may not have been the smartest nuts, but they were smart enough to be able to make turpentine so they had some skills.
My point is that it is very hard to tell the difference between a Jefferey Pine and a Ponderosa - especially given that there are sub-varieties of each (if not named there is still variation as with any species.) I think that the best way to tell is to smell them - no smell is Ponderosa, vanilla-pineapple, or something like that - Jefferey. I own four "Ponderosa", one of them smells quite distinctly, almost all the time, the others have no smell, the buds and needles all look nearly identical. I've never seen a cone on a collected Ponderosa, but that would be one way to tell - Ponderosa I believe have much larger cones - or is it the other way around...? I'd have to go check my book to be sure.
I hate to bring up old controversies but the fact remains that you seldom see bonsai of some of the most beautiful candidates that grow native to America. My two favorites currently on the MIA list are collected Bristle Cone Pines and collected or even cultivated for that matter, White Bark Pines. As near as I can tell the problem with the former is cultivational; as to the latter, the White Bark Pine, I must claim total ignorance.
The point may be that the Jeffery Pine may not accept bonsai cultivation favorably, or it may have never been tried by the caliber of grower that would be necessary to work with a tree having what could be called a difficult needle length not off set by a spectacular trunk and bark making collecting one worth the time and effort. Again pleading ignorance; it is possible that this tree does not, or will not survive in the kinds of conditions that cause a collectible Yamadori.
There is one example of the Jeffrey Pine on Page 239 of the John Naka book Bonsai Techniques II - a collected tree.....as for the Whitebark Pine...if collectors focused on this tree I am sure collected specimens could be located and collected - for the most part the pine of choice collected from the wild is the Ponderosa Pine......Tom