In last years 5280 Magazine Denver's Best Schools there were a few private Christian schools that were rated. Including:
St. Mary's Academy High School (Englewood)
Regis High School (Aurora)
Bishop Machebeuf (Denver)
You can see the 5280 Article at: http://www.leslieheldenbrand.com/denver-news-articles.asp
If you have any questions please let me know!
Our daughter started kindergarten there and is now in 7th grade. She will need to test into High School as they do not automatically offer enrollment.
It has been one of the best decisions we have made.