It was a spectacular day in Yellowstone, sunny and clear until early evening. It is, however, at a high enough elevation to put a nip in the air and require an extra layer. We rose early at Norris Campground and made our way down to the Old Faithful visitor center. We arrived just in time to see Old Faithful spout from a little way off. Turns out she spouts on average every 93 minutes, so we took a nature hike around the boardwalk above Old Faithful which passes by twenty or thirty geysers and hot spring pools. They are very impressive to look at and the 93 minutes went very quickly, with us arriving back just in time to see the Old Faithful's next blast. We then spent enough time on the (pay) phone with our new cell phone provider to see Old Faithful erupt again...We got a little lunch at the Geyser Grill and headed on up the road back toward Norris Campground, pulling out at various geysers and mud pots and making the detour up to Yellowstone Canyon for a hike to the lower falls from Inspiration Point. After our second little hike of the day, we backtracked all of the way to the North Entrance and checked in to the Mammoth Hot Springs campground for the night, with plans to exit tomorrow out the Northeast entrance after a hike up Specimen Ridge to look at some fossils.We drove the five miles back up the road to Gardiner and, on the advice of a local in the Flying Pig Camp Shop, we had some great pizza at the K-Bar saloon.