I was walking in the pasture today and came across an area that had a lot of these plants blooming. This seems like a relatively new plant to me and I've been here a long time. Either the wet year has made it more visible or it's something recently finding its way here. Looks a lot like annual garden phlox as it grows in this area. About the same size. I'm not a good close up photographer, so I hope these suffice.
l to r: detail; a plant; growing in native rangeland: