GENERAL50861

• Permit No: C1989074
• IBM Index Class Name: General Documents
• Doc Date: 5/20/2004
• Doc Name: Review of DMG Vegetation Sampling Data
• From: DMG
• To: American Civil Constructors, Inc
• Permit Index Doc Type: Vegetation
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
1313 Sherman S[., Room 215 C O L D RA D O
Denver, Colorado 80203 DIVISION O F
Phone: [phone] M t N ~ /~ L $

FAX: [phone]
GEOLOGY
RECLANATION•NINING
SAFETY•SCIENCE
Bill Owens
May 20, 2004 Governor
Greg E. Walther
Executive Director
Grant Johns

American Civil Constructors, Inc. Ronald W. Cottony
Division Director
410 20th St., Ste. S-1 Natural Resource Trustee
Glenwood Springs, CO 81601-4272
Re: Review of DMG Vegetation Sampling Data
Rimrock Mine (Permit No. C-89-074)
Dear Mr. Johns:
As you know, for the last two field seasons, the Division of Minerals and Geology has
collected vegetation data at the Rimrock Mine for use by you for a future Phase III bond
release. The Division forwarded these data to you on December 5, 2002 and April 2, 2004,
along with a brief report for each year discussing the data and comparing the results to the
approved revegetation standards. In preparation for sampling again this field season (2004),
we recently conducted a review of the previously collected data and calculations included in
the reports. Based upon this review, we feel it is appropriate to provide some additional
explanation of the data and correct a few identified errors in the report and calculations.
Please refer to the report titled "2002 Vegetation Sampling, Release of Liability, Rimrock
Strip Mine, Trinidad Colorado" dated September 2002. The following errors in the report and
calculations are noted below.
Under the Introduction heading on page 2, the report incorrectly identifies the site as
"19.6 acre mined area north of County Road 120 within the permit area of the La Plata
No. 1 mine". The data included in the report was collected at the Rimrock mine, a
19.6 acre reclaimed area located south of the Engleville Road southeast of Trinidad,
Colorado.
Under the subheading "Vegetation Cover and Species Composition" on page 3, the
report incorrectly states "Cover transects were 25 meters in length, with ten sample
data points collected at 5.0 meter intervals along the transect on both sides of the
transect centerline, for a total of 100 points per transect." Ten sample points were
taken at 5 meter intervals along one side of a 25 meter transect resulting in 50 data
points per transect rather than 100. Please refer to the raw data sheets for further
confirmation.
Office of Office of Colorado
Mined Land Reclamation Active and Inactive Mines Geological Survey