Jean Craighead George books in order
14 books in the catalogue, about 52 hours of reading in all; the shortest takes 1 hour and the longest 7 hours.
3 series and 7 standalone books in the catalogue.
Mountain
5 books 1 
My Side of the Mountain 3.3 h 2 
On the Far Side of the Mountain 3.1 h 3 
Frightful's Mountain 4.7 h
My Side of the Mountain 3.3 h 2 On the Far Side of the Mountain 3.1 h 3 Frightful's Mountain 4.7 h 4 Frightful's Daughter length not known
5 Frightful's Daughter Meets the Baron Weasel length not known
Julie
5 books 1 
Julie of the Wolves 3.2 h 2 
Julie 4.4 h 3 
Julie's Wolf Pack 3.5 h
Julie of the Wolves 3.2 h 2 Julie 4.4 h 3 Julie's Wolf Pack 3.5 h 4 Nutik, the Wolf Pup length not known
5 Nutik and Amaroq Play Ball length not known
Ecological Mystery
4 books 1 Who Really Killed Cock Robin? length not known
2 
The Missing 'Gator of Gumbo Limbo 2.7 h 3 The Fire Bug Connection length not known
4 The Case of the Missing Cutthroats length not known
Standalone books
One Day in the Tropical Rain Forest 1.2 h 
There's an Owl in the Shower 2.4 h 
The Tarantula in My Purse 2.5 h 
The Book of Children's Classics 6.9 h 
My Side of the Mountain Trilogy 4.7 h 
The Kingfisher Book of Great Boy Stories 2.9 h 
Prentice Hall Literature--Timeless Voices, Timeless Themes--Copper Level 6.2 h