Excellent style! This would definitely fit right into a children's book. I really like the colors in the rocky canyon itself. The subtle textures in the blue sky compared to the uniform yellow of the flat ground is a nice contrast.
My main critique is with the snake. Although I like that you've included a snake, the black and white coloring doesn't quite fit in with the rest of the painting. I did some searching and it looks like earth-toned rattlesnakes are native to the grand canyon...I think something like that would have fit in better.
I like the grassy shrubs on the right but because they're quite dense it makes the painting look a little imbalanced. Instead, maybe the grass could be a little more sparse, or have a couple grassy patches on the left too?
Anyway, lovely work, hope this helps!