Where did fresh water fish in high mountain lakes come from?

The fish and waters were there before the mountains. Mountains rise and erode, while sea bottoms like Kansas become plains. Geologic time allows small incremental changes to become very large. This is why larger rivers cut through mountain chains, the river was there first. The mountains began uplifting but the river continued eroding its channel during the process so the mountains pushed up leaving the river on its original level. Look at the Columbia River as it cuts through the Cascade Mountain range to create the gorge. This keeps inland areas connected by waterways despite mountain barriers.

http://www.geology.wisc.edu/~maher/air/air15.htm

The Winooski River predates the ancient Green Mountains in Vermont so this river saw these mountains as they rose and eroded.

Alpine lakes & streams can be isolated remnants of old smaller water courses or glacial in origin. Glacial lakes that begin barren of life can become stocked by birds or other means that transport viable fish eggs, plankton and water plants up stream. 1/2 a million years ago western North America experienced a much wetter climate, and many basins were occupied by giant lakes. The climate changed, and dried, reducing the inland lakes & isolating the fish.

Fresh water fish recolonized all of the present-day rivers and lakes that were under ice during the Ice Age. Many lake dwelling fish will enter streams to spawn, like the Yellowstone cutthroat trout, so move through and between river systems downstream or upstream to lakes. Streams change courses over time so what is currently possible for their movement was not true thousands of years ago.

A great example of life restored to an alpine lake is Spirit Lake on Mount St Helens. This lake received hot volcanic rocks and was shifted as the land rose more than 200 feet beneath it. This left the lake shallower and broader and filled with dead trees from the blast.

“The water was black,” said Larson in 1980 describing the post-eruption Spirit Lake as “a roiling, steaming body of degraded water choked with logs and mud.” This was toxic to aquatic life at the time.

It took a few years for the Lake to clear itself and regrow the rich bottom plants and plankton. All of these colonized naturally.

The fish may have come from nearby lakes out of the direct blast path.

http://www.fs.fed.us/gpnf/mshnvm/education/teacher...

Of course altitude plays a part in how much diversity colonizes and survives in an alpine lake. Very high lakes that remain icebound much of the year show less diversity of species than lakes at lower elevations.

Some freshwater lakes have been seeded with fish, but many now unconnected lakes were at one time connected. At the end of the most recent glacial age, they were due to the massive influx of melted glacial water which has now receded. Even today we find sea life in unexpected places. Two days ago, a man in Nunavut ice fishing in a supposed inland lake caught a Greenland shark. The shark either came in through an unknown underwater channel or during a thaw.

A long, long time ago fish from the sea followed rivers upstream to populate fresh water. Mountain lakes kept their fish as the streams dried up under changing climate conditions and the lakes lost their sea connection. So now fish live in remote, isolated mountain lakes.

"Of course, if there are dams on the lakes, likely some natural resource agency stocked the fish following construction"

Some creatures did travel to fresh waters in mud on the feet of birds-freshwater sponges, moss animals, and jellyfish-but not fish.

About 400 to 500 million years ago, ancient fish made the move from salt to fresh water because, then, fresh water posed no threat to their survival. A stiff covering of bones formed a skin and stopped water from entering their blood stream faster than their kidneys could push it out.

These primitive fish are largely gone, vanquished by the many changes in Earth's continents and her vast drainage systems. New immigrants from the sea have taken the ancient ones' places. A few of the old ones remain: a sturgeon in northeastern North America and the garpikes in the Great Lakes. The last large invasion from the sea happened about 70 to 150 million years ago.

The newer fishes spread across Asia northeastward into North America but most maintain their fish family headquarters in the sea. Some fishes, like the salmon, live in the sea and return to fresh water only to spawn. Other fish maintain their tolerance for brackish and saltwater even after hundreds of generations in lakes and streams: like the mud minnows, the pikes and pickerels.

I'm not an expert, but depending on how genetically different they are from other species from different areas, they could have got there before the mountains fully formed. I guess this depends on the mountains themselves.

I suppose it is also possible that they go there while glaciers were melting. At this time there would have been more waterways and the lakes would have more of a connection with the outside world.

I thick they travel through under ground rivers. Under ground rivers are connected to surface rivers in some areas.

They probably originated there when the world was just water, then stayed there when the waters receded - like giant rock pools!

Im not a zooologist, but my best guess was fish eggs were transplanted there posiblly on the legs of water birds ???

australia, no but native aquatic animals here can go with out water and can travel on the legs of birds.

for hundreds if not thousands of killometers between water holes.

from fish seeds

The flood