One of the most common fish for ponds here in Colorado is Koi. A professional Koi pond is built very deep with no rocks inside of it – a liner only. It should be smooth and deep, otherwise the Koi could scrape themselves off the rocks. If you want to learn more about Koi, we recommend joining the Rocky Mountain Koi Club.
There are a lot of critters in Colorado so to ensure the safety of your expensive koi you have to take measures to protect them from Raccoons, Herons, Kingfishers and snakes.
Native fish like perch are also an excellent choice for your fish pond.
Minnows are helpful as they take care of mosquito larvae. However, if you have good flow in your pond, you don’t need to worry about mosquito larvae since they prefer still stagnant water.