Rock Art - Petroglyphs, Pictograms, Geoglyphs and other non-verbal communication:
Communication by the ancients who inhabited Utah and the surrounding states, particularly in the four-corners area is realtively prolific. New petroglyphs are found regularly and I believe people have now come to understand not to add to these ancient works of art / communication and preserve them for the future. This page is dedicated to showing the work done by these inhabitants of this part of North America.
I will add photos of geoglyphs discovered in Peru that are enormous. The image of the character with what appears as antenna or dreadlocks protruding from is head, three straight up and three sticking out from each side of the head is 120 meters (yards) in length. There are a series of these large geoglyphs that cover an area of approximately 50 sq. kilometers. Who or what were they communicating with?  Communication, obviously, important to ancient man.  

Newpaper Rock  

Newpapaer rock is on State Hwy. 211, the only road that leads to the south entrance to Canyonlands National Park.  It is approximately 19 miles from Hwy 191, the Highway between Moab, Ut. and Monticello, Ut.  Newspaper Rock is known to be one of the most important petroglyphs in North America with entries made over several hundred years by a variety of cultures or tribesTake note of how many of the feet etched into Newpaper rock have six toes. Why? Will we eventually end up with four or three toes?  
Peruvian Geoglyphs
Nazca lines are located in the south of Peru and are a group of geoglyphs that extend in the pampas of Jumana.  They encompass an area of nearly 1,000 square kilometers. Aracama Giant is 119 meters (yards) long.  There are about 300 different figures.  These figures were created between 900 - 1,450 AD  Some are up to 30 meters (yards) wide and more than 9 kilmeters long.  A landing strip for some ancient air-born craft?  
The Kokopeli petroglyphs are found in Mexico.