Motorized pumps were first installed in the Dutch Windmill in 1913 to augment the power system, and the Murphy Windmill was electrified soon after. It is commonly believed that the windmills were taken out of service around 1935, after which they began to deteriorate. A campaign to restore them began in 1964, but funding difficulties caused the Murphy Windmill to be dropped from the plan. Cosmetic repairs to the Dutch Windmill were completed in 1980, but it no longer functions. The Murphy Windmill is now undergoing extensive restoration.
The Queen Wilhelmina Tulip Garden, planted just below the Dutch Windmill, features thousands of tulips interspersed with Icelandic poppies, which burst into glorious flower in March and April.