Hi Kari!
Thanks for stopping by with your question. Guests are permitted to bring backpacks, purses, or small bags onto the rides. As long as your backpack is within the size limit (no larger than 24" long x 15" wide x 18" high for suitcases, coolers or backpacks) you can carry it in to the parks. For a list of types of personal items not permitted inside the theme parks,
click here.
I always take a backpack or a small bag on the attractions with me. If it is a thrill ride like Big Thunder Mountain Railroad, I make sure to loop one of the straps around my leg. A lot of the rides, including Big Thunder Mountain Railroad, have small pouches in front of your seat for loose, personal items. I've stored sunglasses and hats in them without running into any problems. Another option Guests have is renting a locker. Each theme park offers
locker rentals, which can be opened and closed as often as you like throughout the day.
Please let me know if I can assist you with any other questions regarding your visit to Walt Disney World Resort.
Have a magical day!
Bob