3 RIVERS PHOTO GALLERY. 3 Rivers Petroglyph Site is near Alamogardo NM. A BLM Park staffed by a live-in custodial couple with adjacent Campground. Across the street is a small pueblo ruin. Thousands of glyphs done by the Jornada Mogollon people between 900-1400 AD run along a cliffside. For more information about 3 Rivers Petroglyphs, click HERE. Click on the first thumbnail to see larger image. Use controls at bottom of each large image to start slide show or go through manually with arrow keys.