Please Let the BLM know the Sombrillo ACEC needs better protection

The section of the Sombrillo ACEC highlighted here (8,587 acres) has recently experienced significant resource damage due primarily to irresponsible mountain bikers creating illegal trails, riding across delicate biological soil crusts, widening trails, stunt riding on fragile stratigraphic features protected under the ACEC.  Immediate safeguards are needed to curb these damages, many of them being irreversible.  The proposed BLM Public Lands Rule calls for better management and protection of ACECs.  Let’s convince the BLM that the Sombrillo ACEC needs better protection; now is the time to do it.

The northern segment of the Sombrillo ACEC (8,836 acres) has suffered extensive damage from mechanized travel.  Let’s protect the southern segment of the Sombrillo ACEC (8,587 acres), rich in significant paleontological and geologic resources before it too gets destroyed.

How to the BLM can better protect the Sombrillo Area of Critical Environmental Concern

1. Protect Intact landscapes – in the past, the Sombrillo ACEC was an intact and healthy landscape; however, in recent years, and with a lack of protections, the land is degraded and is no longer intact or healthy.

2. Restore landscapes back to health – the fragile habitat within the Sombrillo ACEC needs to be restored back to health after recent abuse.

3. Ensure wise decision-making based on science and data is used to manage the Sombrillo ACEC.  Its fragile soft-soil ecosystem, paleontological and geologic resources, and culturally significant and scenic formations require special protections unique to this ACEC.

Here are specific actions the BLM needs to take to better protect the Sombrillo ACEC.
  1. Restore the landscape where trails were illegally developed on protected, highly-erodible ridges, sensitive reference stratigraphic structures, and fragile biotic soil crusts.
  2. Work with neighboring pueblos to maintain indigenous sacred features and ridgelines in the Sombrillo ACEC.
  3. Move livestock grazing out of the Sombillo ACEC, as the land does not meet rangeland health standards.
  4. Implement a Limits of Acceptable Change (LAC) framework to monitor, measure, and manage the impacts of mountain biking in the Sombrillo ACEC.  Use this to establish sustainable trails and close trails that cannot support mountain bike use while also protecting the resources of the Sombrillo ACEC.  Measure the impacts of biking (number of new trails, widening of trails, number of off-trail riding, amount of riding on biotic soil crusts, and other erosion measures).  Communicate via trail signage, internet communications with bike clubs, leaderboard sites (Strava, Trailforks, etc.), and bike clubs that these limits are not met, the entire Sombrillo ACEC will be closed to all bikes.   The LAC framework sets known limits for the biking community to abide by.

The comment period on the proposed rule will end on July 5, 2023.

Please see the BLM presentation slides on the Proposed BLM Land Use Rule and make your comments on this BLM page.

Steps the BLM needs to take to prevent the increasing damage to the Sombrillo ACEC

  1. Close all illegally constructed trails to mountain biking.  Post official BLM signs on these trails prohibiting bike use on them.
  2. Official BLM takedown notices sent to,, and other social media leader-boards to remove all unauthorized and illegal trails in the Sombrillo ACEC from their online presence.
  3. Official correspondence from BLM to mountain bike clubs of the specific trails closed to biking.
  4. Initiate a limited acceptable change (LAC) evaluation of user impacts to the Sombrillo ACEC with consideration of permanently closing this entire section (8,575 acres) to all forms of mechanized travel if certain damage criteria are not met.
  5. Re-evaluate and permanently retire, through buy-out programs, all grazing permits in this section of the Sombrillo ACEC.

Contact the BLM

Pamela Mathis, BLM Taos Office, Field Manager. (575) 758-8851

Melanie Barnes, BLM New Mexico Office, NM State Director.  (505)-479-2240

(c) Copyright - Friends of the Nambe Badlands / All Rights Reserved