After 15 years in the making, the group Save Mount Diablo has successfully bought a $1.04 million conservation easement to forever protect 154 acres of open space on Mount Diablo’s North Peak.

The nonprofit land trust initially signed a two-year option agreement with the Concord Mt. Diablo Trail Ride Association to provide ample time to raise funds for the legal agreement.

Before obtaining a conservation easement, the land was falling vulnerable to development. Save Mount Diablo said more than 15 houses and buildings were built near the now-conserved area. Now, any activities and development on the land will be restricted.

“This agreement will assure that future generations will be able to fully enjoy the natural beauty of this area of California without the threat of development. Save Mount Diablo took into consideration the history of our equine needs while sculpting the agreement,” Diane Jorgensen, a board member with the trail ride association, said in a statement.

The property is part of the “Missing Mile,” which is a privately owned piece of land surrounded by Mount Diablo State Park on three sides and adjacent to Save Mount Diablo’s Young Canyon and North Peak Ranch.

The property is also rich in biodiversity, mostly due to the unique geology of the main peaks, like the serpentine soils that foster rare plant species like the Mount Diablo globe lily.

“This agreement affords us the security of knowing that a beautiful piece of the mountain will be forever protected from urban development without sacrificing land ownership. The heritage of horses on Mt. Diablo can continue indefinitely. We are eternally grateful that Save Mount Diablo has been so supportive and patient, tirelessly navigating us through the entire process. I hope that other landowners will follow in our footsteps to protect their land too,” Elaine Baker, board president for the trail ride association, said in a statement.