As (modern) treatment and prevention of tuberculosis became more prevalent, the requirements for the traditional isolation sanatoriums lessened. Decreased occupancy resulted at the Muskoka hospital during the late 1940’s and throughout the 1950’s. Meanwhile, a counterbalancing phenomenon in the field of mental retardation began demanding increased care and treatment space.
In 1960, the 62-acre site, a rocky peninsula jutting out into Lake Muskoka and the existing structure, were acquired by the Ontario Department of Health as an extension of the Ontario Hospital School at Orillia.
In 1973, the facility administered to 305 female patients between the ages of 16 to 80 years with the total staff of about 300. There were also four male adolescent resents. About 275 of these residents occupied the large Gage complex, built in 1922, with the remainder housed in the Barbara Heyden Residence, constructed in 1936.
The Muskoka Centre was closed in 1994.
Some buildings already have been pressed into 're-use' by the O.P.P (Ontario Provincial Police) who run canine and SWAT training.
Thanks, uer.ca, for the information (urban exploration resource, an excellent site for all of us mischief makers).