A good Realtor that you know can help with this. Also, it you have a relationship with a title company you have worked with to sell or purchase a home may help you with this as well. Hope it all works out for you.
Robert McGuire ASR
Your Castle Real Estate
Direct - 303-669-1246
Go online to the county assessors site and do a search and you should be able to find some comps. You should be able to find some sales in the area of the home you want comps for. (street, subdivision, etc.)