I remember hearing how the Colorado river had to flow up hill in order to carve out the Grand Canyon, so when I did some googling I found the below and thought I would share it!

Two people can often look at the same thing and come to opposite conclusions. The Grand Canyon is a perfect example. Evolutionists use it as proof that the earth is billions of years old, claiming that the Colorado River carved the canyon over millions of years. Bible-believing Christians interpret the canyon as a spillway from Noah’s Flood. One believes it formed slowly, with a little water and a lot of time. The other believes it formed quickly, with a lot of water and a little time. What a stark difference!
If the Bible is true, and the earth is only about six thousand years old, we should find evidence that debunks the evolutionist theory about the Grand Canyon. We do. For example, the top of Grand Canyon is over four thousand feet higher than where the Colorado River enters the canyon, meaning it would have had to flow uphill for millions of years. Additionally, in contrast to all other rivers, we do not find a delta (a place where washed-out mud is deposited). This alone makes the evolutionist interpretation impossible.
The evidence does, however, point to Noah’s Flood. Today, we see two beach lines from what used to be two large lakes near the Grand Canyon. Creationists believe that after Noah’s Flood, the lakes got too full and spilled over the top. When water overflows a dam, the weakest point is instantly eroded. Thus, the Grand Canyon would have been formed quickly, supporting the creationist interpretation.
So, which interpretation is right? Knowing that rivers don’t flow uphill and no leftover sedimentary deposits are found, evolutionists have a lot of explaining to do when it comes to the Grand Canyon. The Bible, however, says that a flood covered the whole earth (see Genesis 7:18-20). This means we should find places where the water drained. The Grand Canyon is one of those places. It is a washed-out spillway and provides great evidence for Noah’s Flood.
https://creationtoday.org/did-the-colorado-river-flow-uphill/