Register Now for the Gladstone Convention! Due to tour bus limitations, registration will be limited. No walk-in registrations will be allowed.Registrations must be received by September 7, 2024 2024 Convention Flyer 2024 Convention Registration Gladstone depot in 1986. Photo by Mark Simonson. Like Soo Cabooses? We are in the process of publishing two Soo Line caboose books; one for the International Wide Vision cars 1-45, the other on wood cabooses. We are looking for stories and photos of the Steel Cars.See link for details Soo Line Caboose Book SLHTS Collection