Completed in 1963, this dome housed several 4 to 8-inch (10 to 20-centimeter) telescopes used for observing the solar surface and atmosphere. Like the Evans, the roof of the building rotated around to allow the telescopes to track the sun as it moved across the sky.

Hilltop was utilized for the "daily flare" patrol and to record everyday events such as sunspots and flares. Maintenance costs and other new and improved instruments caused the observatory to close in 2014.

For many years a televised image was broadcast from Hilltop on the local TV station for residents of Sunspot to see.