The Midway Geyser Basin's Grand Prismatic Spring is the largest ... produced by the water around the hot spring. The center looks blue, but actually isn't – the blue wavelengths of light are ...

U.S. News Insider Tip: Some visitors, especially kids, might have respiratory discomfort at Norris Geyser Basin, as the sulfur smell can be strong. – Catherine Parker Old Faithful may be ...

Lower Geyser Basin, including Fountain Paint Pot Trail ... where you will run into several springs, including Blue Star ...

The Midway Geyser Basin boardwalks also take you past Excelsior Geyser, a beautiful blue dormant geyser. The Excelsior Spring ...