Link 1 is the link for the parks' website! If you plan to enter the park through the West Glacier (Apgar) entrance or North Fork entrance between 7am-3pm you MUST obtain a timed entry vehicle reservation. Download the mobile app Recreation.gov - the tickets can ONLY be purchased through Recreation.gov. They are $2 a piece, are per vehicle and are good for 1 day only. A portion of the tickets are released at 8am MST 120 days prior to the date you plan to purchase for. The rest are released the night before the date you plan to purchase for. They are a timed entry (which must be observed) so you must select the time slot during which you plan to enter when purchasing the ticket. **The park is most quiet in the evening & with the late sunsets, entering the park at 3pm leaves plenty of time to still drive the whole road in day light. If you are planning a big hike, you’ll want to enter the park before 7am for parking. Get on the app just prior to 8am MST on the date that coincides with the date you are needing a ticket for so you are on and ready for them to be released. Tickets are NOT needed to enter GTTSR from the St. Mary entrance between 7am-3pm, HOWEVER this entrance is on the east side of the park with a longer initial drive over. Please Note: you CANNOT get to GTTSR from Two Medicine, these two areas of the park do not connect. A general park pass is not the same as the ticketed entry system. These are two separate things. Regardless of when you plan to enter the park and which entrance you plan to use, a general park pass is NEEDED for every vehicle entering at ANY entrance. These can be purchased at the time of entry if needed. (They only accept card payment at the gate.) It is $35 for a week and that will work for any of the entrances. They can also be purchased ahead of time online (link 2). If you plan to obtain a ticketed entry ticket, you will still need a general park pass on top of it. Links are below in the "LINK" question.
Link 1: https://www.nps.gov/glac/planyourvisit/vehicle-reservations.htm Link 2: https://www.nps.gov/glac/planyourvisit/fees.htm#spci_07223807-C1AD-ADFA-F12D2883AFAE6166