You can write to Malik at:
Malik Muhammad #23935744
Snake River Correctional Institution
777 Stanton Blvd
Ontario, OR 97914-8335
Malik can also receive communications electronically, and prefers that method for consistent correspondence. You can find instructions for setting up electronic messages via the GettingOut website here:
https://www.icscorrections.com/docs/Gettingout_instructions.pdf
*Note that you must first send your email address to Malik in writing so that he can add you to his list of approved contacts.