This is a paid asset, but now you can download Maple Trees Package for FREE, but please remember this package is provided only for learning purposes or to be able to test before buying the product, NOT FOR COMMERCIAL PURPOSES.
Detail this asset from Unity Store: Original Link
Maple Trees Package v1.1 (Latest version)
This package contains 8 fully editable maple trees ready to use right out of the box: collision already set up, bending is carefully tweaked on each level of any tree and textures will import with settings giving you the best possible look.
Explore the trees!
Specs
Height: 6 – 20m
Tris: 770 – 5300 on current LOD
Textures: [Leaves] d/ n/ t – [Bark] d/ n / gl
Shared materials for all trees in order to save up texture memory and bandwidth.
Fillrate optimized meshes for leaves.
Highres diffuse texture for bark and leaves [2048 x 1024px]