I did find and finished The Camp Fire Girls in the Maine Woods, the first of the Hildegard Frey series which introduces then-snobbish Gladys to the girls, who chiefly go by their Camp Fire nicknames: Sahwah (Sarah Brewster), the athletic girl who loves to swim; Hinpoha (Dorothy Bradford), the chubby one who is later left in the guardianship of her stuffy Aunt Phoebe; Migwan (Elsie Gardiner), the literary one who wants to attend college; Nyoda (Elizabeth Kent), their "den mother," and Nakwisi, Chapa, and Medmangi (I'm not sure if we ever learn their names). Gladys always remains Gladys in the course of the books, despite her reformation. I'd love to read all of them, but only half are online at the moment.
I did find a further treat on Munsey's (formerly Blackmask.com), however: more "Ruth Fielding" and "Outdoor Girls" books, as well as pretty much the entire run of "The Moving Picture Girls." I had already read one of the MPG's books, Under the Palms, where they are in the wilds of Florida (don't laugh; Florida was chiefly tropical wilderness at the time the book was written), but am just now reading the first book and finding out how Alice and Ruth and their father Hosmer DeVere originally joined the "Comet Film Company" and came to make "parlor dramas" and other "pictures."
The first book was written in 1914 and it is striking that although the author "Laura Lee Hope" (really one of the writers in the Stratemeyer Syndicate of children's series books and of course "author" of the "Bobbsey Twins" series) comments "I presume all my readers have seen moving pictures many times..." she proceeds to describe the process of making what is now known as the "silent film," since the concept was still so new. She actually devotes an entire short chapter to the description, which shows how much has changed in moviemaking, since all the interior shots were filmed on one big stage with directors shouting out comments to the actors, and California is stated as being a place where the film companies "went on location" to get authentic backgrounds, since the early films were chiefly shot in New York and New Jersey. But then many things have changed: the DeVeres' neighbor in the next apartment, Russ Dalwood, is designing a new motion picture camera and a patent thief is after his plans. Alice visits the Dalwood apartment one day (no key necessary; there are not even locks on the doors!) and finds someone rifling through Russ' kitchen. When they tell him what happened and suggest he call the police (note portion in bold!):
Wow."I'll think about it," agreed Russ. "Of course he hasn't really done anything yet that they could arrest him for, unless coming into our apartment without being invited is illegal, and he could wriggle out of a charge of that sort..."
You can find more about "The Moving Picture Girls" here, and the entire site is great, also talking about Ruth Fielding, Betty Gordon, the Outdoor Girls and other older series, plus later series like Nancy Drew, the Dana Girls, Trixie Belden, etc.
There is also a blog about her reading of these series books.