Nature baby names?!

I am in love with nature names for babies middle name. My first child is named Greyson River. I would like suggestions on nature names that would suit for a middle name. I need boy and girl names! To give an idea of the first names I've been thinking to help out are for girls: Elliot, Blair, and Blythe. For boys: Wyatt and Sawyer. So far that's all I've fell in love with for first names. The only middles names I've found so far are for girls: Moon, and for boys: Sparrow. If any one has any ideas please share!! Thank you 😄