The origin of the unidentified EGRET sources remains one of the great puzzles to solve in &ggr;-ray astronomy. It is increasingly apparent from population studies of their combined spatial, spectral, and temporal characteristics that various kinds of objects are involved. Evidence exists for an important correlation between the positions of the stable sources and active star-forming regions, both in the Galactic disc and locally, in the Gould Belt. Different options as to their nature in these young environments are discussed. ©2001 American Institute of Physics.