Actually, this flower is called Bouncingbet or Soapwort. Found these on the banks of the North Saint Vrain Creek in the Button Dam Preserve.
These 4 inch high Alpine Sunflowers follow the sun, turning their heads in a full circle on sunny days.
Every year I make a special trip to see the Plains Prickly Pear cactus on the Twin Owls Loop. I just think it is cool that these very ugly rough plants develop such amazing flowers. Look in the hottest, sunniest spots you can find.