Some of the smarter 'lights' in America's Galaxy, however.

I believe as you are looking at the faces, you are looking to the Northwest so the faces are angled somewhat towards the east. Here's a park map, note the "North" indicator, lower right:
http://www.nps.gov/moru/ppmaps/k10625%7E1%2Ejpg

Here's the official NPS site:
http://www.nps.gov/moru/

Here's a photo album showing the faces at various times of day.
http://www.travelsd.com/parks/rushmore/photos.htm

Here's a live webcam:
http://www.travelsd.com/website/webcam/rushmore.htm

I was last there on July 4, 1975 while on my way to a camping trip in the Bighorn Mountains of Wyoming (not the Little Bighorns of Custer fame.) The American Indian Movement was having a demonstration at Mount Rushmore (which is built on land sacred to the local tribe.)

I wish I could find that photo I took showing Russell Means, leader of AIM and other leaders with the faces of Rushmore in the background.

Don't forget to rent "Close Encounters of the Third Kind" before you go to Devil's Tower. The Trailer:
http://www.imdb.com/Trailers?0075860&screenplay&E11257&5&3

Yellowstone is one of the most amazing places on earth. Keep in mind you are walking on the top of a volcanic caldera -- one of the largest on earth. It's known to have blown 3 times -- the most recent 600,000 years ago. http://vulcan.wr.usgs.gov/Volcanoes/Yellowstone/description_yellowstone.html