Chugach State Park is issuing special-use permits for winter fat biking on Middle Fork Trail and other trails as listed on the permits. This special access is for bikes with a minimum tire width of 3.7 inches. Every rider must have his/her own permit and it must be displayed on the bike while on the specified trails.
The permits are free, and can be picked up at park headquarters on the Seward Highway at the southern end of Potter Marsh during regular office hours (M-F 10-12, 1-4). If you send an e-mail to firstname.lastname@example.org including your name, phone number and e-mail address, they'll prepare your permit before you arrive, and laminate it for you after you sign it in the office.
Don't forget to thank the staff for accommodating fat bikes!