Highest Mountain and Peaks in each of the US States. Profiles the highest mountain in each of the 50 US states with a brief description, elevation, and ranking. Links to an interactive topo map of each high point. WARNING: Wilderness conditions can change suddenly.
Best Answer: A tethered hot air balloon flight will typically be between 50-75 feet. It's high enough for the passengers to get a feel for the height and manageable enough for rope length. I have heard of some gas ride balloons that are on a winch go higher. To tell you the truth, I can't recall the max height for tethering. It wouldn't be different than for gas balloons.
The atmosphere above 10 km is called the stratosphere. The gas is still dense enough that hot air balloons can ascend to altitudes of 15 - 20 km and Helium balloons to nearly 35 km, but the air thins rapidly and the gas composition changes slightly as the altitude increases.