Go to Stage 1 Coordinates
Count the number of dragonflies on the ground. This number = E
Note: Be careful to not bump your head on the cattails when counting, which I managed to do when I was counting them.
Count the number of cattails. This number = K
Go to Stage 2 Coordinates
How many holes are on the inside of the fake hollowed-out oak tree? This number = A
How many picnic tables are there? This number = J
How many light posts are here? This number = F
Go to Stage 3 Coordinates - Obtain information from the various signs of the following plants:
Keller's Yarrow gets to a spread of __ feet. This number = B
Showy Milkweed gets to a height or spread of __ feet. This number = C
Stick Monkeyflower gets to a height or spread of __ feet. This number = D
Azure Bush Germander's height + spread = __ feet. This number = G
California Buckwheat's height + spread = __ feet. This number = H

You can validate your puzzle solution with certitude.
Congratulations to Sandy Bandy, Wild Drumm & LewisClan77 for FTF!