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BLM CO Areas of Critical Environmental Concern

Published by Bureau of Land Management | Department of the Interior | Metadata Last Checked: January 25, 2026 | Last Modified: 2025-11-18T14:17:35Z
Once a polygon feature leaves the Pre-designated phase (transitions from Considered to Designated), that polygon will be removed from the ACEC Pre-designated feature class and be placed in the ACEC Designated feature class. This data set consist of digital data describing (ACEC) Areas of Critical and Environmental Concern for Public Lands in the State of Colorado. ACECs are designated by decisions made during BLM Resource Management Planning. Existing ACECs have a Resouce value tied to them. An example of these resources would be: Threatened and Endangered Plants. Other areas of concern have also been captured within this theme. When the users opens up the attribute table for this theme the user will notice ACEC follows most of names for each area. Some BLM field offices also included Research Natural Areas (RNAs) and Outstanding Natural Areas (ONAs) with in their layer. The data set was compiled from the most current data collected from the BLM Colorado Field Offices. In some cases data boundaries were snapped to BLMs Geographic Coordinate Data Base (GCDB). The GCDB is a statewide survey grid that BLM bases land boundaries on. Also in some cases within the ACECs outer boundary land holdings other than BLM have been cut out to show these Land Patterns, In other cases it has not. It is suggeted that the user of this data also download BLMs most current Surface Management Agency to compare and contrast land holdings within each ACEC.

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