From 1913-1933, the Outdoor Girls series follows a group of New York girls who form a Camping and Tramping Club. Produced by the Stratemeyer Syndicate under the Laura Lee Hope pen name, the series had twenty-three volumes.
Betty Nelson, Mollie Billette, Grace Ford, and Amy Stonington are often joined in their adventures by four boys and light adventure and romance plots follow. During World War I, the boys go off to fight and the girls do work for the war effort including running a Hostess House.
Later volumes have some of the girls marrying their beau, but the outdoor activities continue. New girls join the group as the series continues.
Camping, canoeing, hiking and other outdoor activities are a main focus for the adventures.