Old Faithful is a cone geyser located in Yellowstone National Park in Wyoming. It was named in 1870 during the Washburn-Langford-Doane Expedition and was the first geyser in the park to receive a name. It is a highly predictable geothermal feature, and has erupted every 44 to 125 minutes since 2000. The geyser and the nearby Old Faithful Inn are part of the Old Faithful Historic District. Wikipedia
Midway Geyser Basin is much smaller than the other basins found alongside the Firehole River in Yellowstone National Park. Despite its small size, it contains two large features, the 200-by-300-foot-wide Excelsior Geyser which pours over 4,000 U.S. gallons per minute into the Firehole River. The largest hot spring in Yellowstone, the 370-foot-wide and 121-foot-deep Grand Prismatic Spring is also found there. Wikipedia