The Wyoming Department of Environmental Quality has a web-cam in the Thunder Basin Ntl. Grasslands 32 miles north of Gillete Wyoming. I look at several web-cams at this web-site: http://www.wyvisnet.com/all.htmlI saw the still image and immediately thought the triangle was peculiar...I saved the image. I'm a little leary about sending it out due to possible copyright problems. I have contacted the webmaster of the site and asked if I need permission to send a still shot from the site to a third party. The site even includes an overlay of geographical landmarks (like ridges) and their proximity to the camera.The next still shot captured by the camera did not show the triangle. I believe the shots are taken in five minute intervals. There is also a "history" of still shots and I saw no triangles in any of these previous pictures.