Jamesia is a genus of shrubs in the Hydrangeaceae, most commonly known as Jamesia, Cliffbush or Waxflower.
It is native to interior western North America, in the U.S. states of Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming, growing in mountains at 1600-3000 m altitude.
It is a shrub growing to 1-2 m tall and to 3 m or more broad, with opposite simple leaves 3-7 cm long and 2-5 cm broad, with a serrated margin and a crinkled surface.
You have encountered cliffbush, first discovered in 1820 in the Rocky Mountains by a botanical pinch hitter, who hit a one-time-only grand slam home run.
And the cheerful aspect of the cliffbush, which must have given James much joy when he discovered it (along with so many other Rocky Mountain plants in full July glory), was apparently not reflected in the discoverer's later years.
James was botanist, geologist, and chronicler on the second season of the 1819/1820 US Army expedition led by Major Stephen Long.