Can anyone help me identify, or figure out how to identify, a plum variety? It was a mature tree nearly 30 years ago when my parents bought their home; another tree of the same variety is planted at a neighbor's, also before he bought, but I have never seen it anywhere else. Located in the Willamette Valley; never treated in any way, but doesn't seem to have pests or disease issues.
Tree is an estimated 30 or 40 feet tall, with odd-angled limbs; it does not seem to throw off suckers. Fruit is clingstone, sweet-tart, appearance that of a small, plum-shaped nectarine; gold with red blush. Flavor is unique. Fruit is on the small side; maybe the size of three or four cherries.

You've done a nice job of describing the tree. One thing you might mention is if the flesh is a different color than the outside skin. I would think about the texture of the flesh too. The texture of apricot , peach, plum and nectarine flesh is different. I can't identify the fruit, but I will tell you that you will more likely get an identification if you include a picture.
John S
PDX OR

Ah, thank you. I believe the flesh exactly mirrors the skin, even to blushing in the same places, and I would describe it as a plum texture. I will have to wait until the fruit ripens to post a photograph.