There are many different types of rocks available in Utah. Some can cause problems. Like sandstone which will disintegrate when the water in it freezes and then there is limestone which will raise the pH level of your pond to levels that can kill fish. Rock selection is very important to both the health of your pond and to your pocket book. One ton of rocks at your local stone store can cost from $40/ton up to $300/ton and you may need up to 3 tons depending on the size of your pond.