On Tuesday, besides visiting Petroglyph National Monument, we also took a short hike through the Rio Grande State Park. The Rio Grande River starts in southwestern Colorado, flows through central New Mexico, into Texas and ends at the Gulf of Mexico. Sadly, because of heavy use of water in the big cities and irrigation of vast farmlands, its discharge into the sea is now a fifth less of its historic output ( according to Wikipedia). We learned, while visiting the visitor's center of the Rio Grande State Park, that the cottonwoods in the park are not reproducing because of low water levels. That is unfortunate because we especially enjoyed the riverside trail which took us through the cottonwood forest. The large old cottonwoods trees are absolutely beautiful right now with their yellow foliage.