I would suggest speaking with an attorney as soon as possible. An attorney can determine if a probate has been opened and the next steps you need to take in the case. From your question, it sounds like your father remarried and his current wife is not your biological mother.
Under Colorado intestate laws (the laws that apply when there is no Will), biological children of the decedent (your father) generally have a right to a share of the estate when step-parents are involved. The amount depends on the length of the marriage and other factors.
Our probate attorneys have experience handling these types of matters. If you would like a case assessment, please contact us at (303) 688-0944 to discuss your options.