The city's population rose from 13,756 in 1920 to 62,736 in 1930. The Forest Lawn Cemetery opened in 1906 and was renamed Forest Lawn Memorial-Park in 1917. Pioneering endocrinologist and entrepreneur Henry R. Harrower opened his clinic in Glendale in 1920, which for many years was the largest business in the city. The American Green Cross, an early conservation and tree preservation society, was formed in 1926 (it disbanded three years later and the current organization of that name is unrelated).