That was my first thought, but the climate doesn’t really change much between the rainforest and glacier. They are quite unique, being semi-tropical glaciers, though.
In Chile’s Atacama Desert. There is no human record of any rain ever falling in parts of the Atacama, but there is agriculture and large cities there because only a few miles away, in the Andes, there is sufficient precipitation to form viable life-supporting rivers into the desert. In some places, ou can literally step from lush green irrigated cropland into a desert where no rain has ever occurred.
I expect a correct, general answer would be on opposite sides of any continental divide mountains. The climate conditions (especially winds & moisture/rainfall) are significantly affected by the intervening mountains, resulting in quite different conditions.
For example, the Rocky Mountains of North America. The prevailing west winds carrying ocean moisture are stopped by the mountains. So the west side is much wetter, with Oregon & Washington, while the same elevation on the east side has much drier & colder areas of Montana & Colorado.
It doesn’t even have to be a continental divide. Just a mountain range tall enough to make the clouds drop their rain when they hit the mountains. The windward side will be relatively verdant. The leeward side will be relatively arid.
Freezing cold to hottest place on earth in a couple dozen miles? This gets my vote.
So a 14,747 foot gain/drop in elevation meets the OP requirement of no “drastic change in elevation”?
The OP said to ignore changes in elevation, not that they were disqualified. So if elevation changes are eliminated, then Whitney/Bitterwater is disqualified.
[QUOTE=OP]
Let’s ignore drastic changes in elevation (I’m sure the top of Kilimanjaro is quite a bit less hospitable than it is down at the bottom).
[/QUOTE]
That would seem to disqualify Badwater/Whitney.
Stand on the equator. One side is summer, the other is winter!
Okay then, the West Portal Tunnel in San Francisco. The West side is perpetual Winter, and the East side in Noe Valley enjoys Spring and Summer sometimes on Spring and Summer days.
The Black Hills of South Dakota may not have different climates but many records for fastest cold drop (like say fastest in one hour, in one day) have been set there.
The principle is correct, but your geography is way off. The Continental Divide runs through the Rockies in Colorado and Montana, but it’s many hundreds of miles to Oregon and Washington. The mountains of those states are the Cascades.
There is some rain shadow effect in the Rockies, but it’s not that great because there’s not that much moisture in the middle of the continent and both sides of the Divide are fairly dry. The Cascades are a better example, with the west side extremely wet and the inland side much drier.
Just in case people aren’t familiar with the Columbia River Gorge area I mentioned earlier, it cuts thru the Cascades without a great deal of elevation change (less than 100ft).
It’s the only such cut thru the Cascades or Sierra Nevadas.
The Rockies don’t have nearly such a drastic change between east and west sides within the US. And places with the least elevation change, like South Pass, also have the least change in climate and vegetation.
The biggest rain shadow for coastal ranges in the western US in on the east side of the Olympics. Sequim, WA gets less than 16 inches a year while elsewhere there can be as much as 150 inches on the west side. However, Sequim still gets a lot of marine air so it doesn’t feel so dry. Still well forested. One can drive via 101 from the west to the east side of the Olympic Pennisula without too much change in elevation.
Like I said, the gorge probably the most easily traveled and drastic change in the US 48 that satisfies the OP.
I would be curious to hear about similar places around the world, myself.