A nationwide statistical survey of training schools, forestry camps, ranches, and diagnostic and reception centers for long-range treatment of delinquent children was conducted in 1966. Of the 304 known institutions in the United States, 292 returned reports. Approximately 51,000 children (79% boys) were living in the facilities, an increase of 16% over 1964 and a rate of 195 per 100,000 of the total child population in the country (aged 10 to 17). Further findings were as follows: in over 50% of the institutions, children stayed 8 months or less; 80% of the institutions were operating under state, and 20% under city and county auspices; 38% had a capacity for over 150 children, the maximum capacity recommended by the Children's Bureau; and four out of 10 were overcrowded. There were 2.2 children for every full time employee (administrative, treatment, educational, operational, and maintenance). Average per capita operating expenditure was $3,345 and a total of $184 million spent by all institutions, a 37% increase over the 2-year period from 1964 to 1966. Findings are summarized nationally and by geographic divisions in the 19 tables. (SN)