Establishing residency for tuition purposes is not automatic. The Department will NOT cover non-resident tuition if you qualify for Colorado residency and neglected to establish it in time.
The tuition classification process begins with the admissions office through their Tuition Classification form. After a student has committed to attend Mines, the student must fill out their Tuition Classification form accurately and honestly (in accordance with Student Conduct policy and the Honor Code), as well as provide all required documents. The tuition classification determined at this time will remain in effect unless a student’s situation changes or additional documentation is provided, proving domicile and intent for 12 continuous months prior to the start of a given semester, at which time the student can submit a petition for reclassification.
Find additional information and petition deadlines here: https://www.mines.edu/registrar/tuition-classification/