I had received a reply from Dawn about my question as to why peach trees do not bloom. She asked for more info. The trees are in full sun. They are seedlings that I got from Colorado and Ohio. I don't know what kind of peaches they were from. In my original message I made a mistake, I am in Larimer County not Apprahoe.
While peaches on dwarfing or semi-dwarfing rootstock could be expected to flower in 3-5 years, a peach on its own roots or other standard-size trees budded onto standard rootstock could take as long as 10 years to flower.
Your trees are in full sun, so shade from nearby buildings shouldn't be a factor.
Over-fertilization with high nitrogen fertilizer can result in luxuriant leaf growth at the cost of flowers. Since most home fruit trees are located in the lawn area, this is a common practice, resulting in few or no blooms.
Although last spring we didn't experience our usual late frost, peach trees tend to flower early. This timing kills the flowers during March or April cold temperatures.
Finally, too little water during drought will stress a tree, preventing the formation of flowers.
I hope these factors will help you identify the reason your peach trees haven't bloomed.