I don't know about Montana specifically, but I'm from Ohio and I went to college in Tennessee.

My doctor in OH would write the prescriptions, and my parents would mail them to me. I never had any problem filling those prescriptions in TN. After my OH doctor moved to another area, I transferred my medical records to the campus doctor who was able to write the prescriptions for me. After I moved back to OH, I just had to find a doctor that was taking on new patients and transfer my medical records. The only problem I had then was that I had to wait 2 months for an opening (because a new patient appointment is longer). Luckily, a doctor a local urgent care facility was willing to write a prescription for one month, since I was between doctors.

See if your current doctor will either write post-dated prescriptions or mail the prescriptions for the first couple of months after your move. You should also make sure you have about a month's supply when you leave Washington (just in case).

When you get to Montana you will need to find a doctor willing to write your prescriptions, and transfer your medical records to his office. Keep in mind it may take a couple of months to get in to see a new doctor.

Here's a link to the Montana State Laws concerning Controlled Substances: http://data.opi.mt.gov/bills/mca_toc/50_32.htm

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