This is a Pacific or Western plum (Prunus subcordata, Bentham) and it is a native species found growing wild in a relatively limited region east of the Coast Range from southern Oregon to central California. It occurs in greatest abundance in Lake and Klamath counties in Oregon and Modoc and Sierra counties in California. While the greatest concentration of the native thickets in California seems to be in the general vicinity of Mount Shasta, the plum is found in more or less abundance east and south of the Nevada line, especially in the foothills of the Sierra Nevadas. It has been reported as far south as Yosemite Valley. The plum usually forms thickets of small to large shrubby trees along streams in canyons, on hillsides, or in the open area of pine forest. In other cases the thickets are found on ridges which are thought to be the shore lines of prehistoric lakes. There is a general similarity in the sites on which the plum thrives and spread throughout the region, so much so that one can almost predict the location of the thickets. The largest trees are found in these thickets growing on the deeper, sandy-loam soils in the canyons where water is ample, and the richer bottomlands adjoining the old lake beds. The hardiness of the species and its ability to adapt itself to adverse conditions is typified by the scrubby little thickets found growing out of rock slides at high elevations. An occasional thicket is found, however, where drought or exposure has all but killed out the stand. The region in which the plum is native has an elevation of 1,000 to 5,000 feet, although it has been observed growing in favorable locations in the mountains of the region at elevations as high as 6,000 feet. At these higher elevations the plums are less apt to bear crops and are late in ripening.

If the colour of the fruit (not petals) is accurately reproduced in the photo it is rather a pale pink for E europaeus. They are usually a more shocking pink colour. They are prettily sprinkled through our hedges at this time of year.

I figured it out. Seems like it's Symphoricarpos orbiculatus aka Coralberry, Indian currant, or Buckbrush

It looks like a black cherry to me, too, although the leaves are less elongated than mine. It might be a choke cherry -- their berries are more purplish than black and the leaves are shorter. Some black cherries are better than others. Mine is quite good, but no matter what you make out of it, it's hard to shake the feeling you are eating cough syrup. You may want to post these pictures in the Tree forum, and add a pictures of the bark as well as the full tree. Wild cherries are a common tree throughout the east coast.