The District faces many issues and choices in managing its land and resources:

• The 26 preserves present a constantly changing mosaic of complex ecosystems with a wide variety of qualities and purposes.
• Land stewards must be able to distinguish and decide among competing priorities. There may be conflict about proper values or actions to take.
• Ecosystems evolve, the amount of land managed by the District changes, and the public's interests and use differ over time and place.

The District calls its lands "preserves" rather than "parks", emphasizing its goal of resource preservation. Resource Management Policies help maintain consistent and effective resource management in light of these changes.