Thank you for your question and I'm very sorry to hear about this situation.
You touch on the main issue involved here, i.e., whether you are an At-Will employee. I assume you know this already, but for the sake of due diligence, here's a brief explanation on the At-Will Doctrine:
In Colorado, and throughout the United States, employment law
heavily favors the employer in most situations. Unless the employee has a contract which provides that the employee may only be terminated for cause, the law will hold that the employee's right to work
falls under the At Will Doctrine. The At Will Doctrine provides that an employer may terminate an employee for any reason whatsoever, even if it is a false reason. The only limitation on this is that an employer may not terminate an employee because of discrimination
based on race, color, religion, sex, military status, national origin, disability, age, or ancestry of the employee.
That being said, do you have any sort of employment contract
Is there any company policy that says that in a situation like this, the company should look internally to transition an employee over before making that employee redundant and hiring from an outside source?
There is a smacking of potential age discrimination
here. Were you the only one whose position was eliminated? Do you know if they are going to hire a person younger than you?