Here is the full list of where each Summer Camp Collection comes from.
Standard doubler boosts will work to double collection item drops for the following items:
Camp Canoe: Espresso Boost
Camp Canoe: Espresso Boost
Campground, Cavern Cave, Cascade Waterfall: Shearing For Shave Tails or Animal Magnetism on first 9 tends but NOT the last tend that heals them.
Stag Prince, Cave Bear, White Wolf: Shearing For Shave Tails or Animal Magnetism
Algae Pools: Crop Whisperer or Crop Mumbler.
Campground Collection
Comes from:
Camp Canoe
Campground ("Healable" Animal in Market)
Stag Prince (Mission Reward Animal)
Algae Pool (Free Gift Crop)
Cavern Cave Collection
Comes From:
Camp Canoe
Cavern Cave ("Healable" Animal in Market)
Cave Bear (Mission Reward Animal)
Algae Pool (Free Gift Crop)
Cascade Collection
Comes From:
Camp Canoe
Cascade Waterfall ("Healable" Animal in Market)
White Wolf (Mission Reward Animal)
Algae Pool (Free Gift Crop)