Officials said rain on Saturday allowed ground crews to work safely on the more remote areas of the fire in the southern area of the park, which has grown to more than 35,000 hectares.
READ MORE: Cottages destroyed in Saskatchewan wildfire
Over 200 personnel are fighting the wildfire. They are being supported by nine helicopters and 10 pieces of heavy equipment.
Firefighters are creating control lines east and west of the fire and patrolling the south boundary to ensure the containment of that part of wildfire is secure.
Fuel from around buildings is being thinned or removed, and sprinkler systems in and around Waskesiu have been tested.
A large portion of the park remains closed but Waskesiu townsite and trails, along with Waskesiu, Hanging Hearts and Crean lakes are open to the public.