REP08251

• Permit No: C1980007
• IBM Index Class Name: Report
• Doc Date: 4/25/2007
• Doc Name: 2005 Subsidence and Geologic Field Observations
• From: Mountain Coal Company, LLC
• To: DRMS
• Permit Index Doc Type: Subsidence Report
• Media Type: D
• Archive: No

TABLE OF CONTENTS
Paae
1.0 SUMMARY OF MAJOR FINDINGS ................................................................................1
2.0 RECOGNITION OF SUBSIDENCE AND NON-SUBSIDENCE FEATURES ...................4
2.1 Subsidence Cracks and Compression Features .................................................................4
2.2 Construction Cracks ............................................................................................................5
2.3 Desiccation Cracks ..............................................................................................................5
2.4 Gravity-Induced Tension Cracks .........................................................................................6
3.0 OVERVIEW OF FIELD STUDIES DURING JULY 2005 ..................................................7
~ 4.0 BOX CANYON, WEST FLATIRON, AND APACHE ROCKS ..........................................8
4.1 Traverse A-A' ....................................................................... ................................................8
' 4.1.1 Location 1 .......................................................... ................................................8
4.1.2 Location 2 .......................................................... ................................................9
4.2 Highway 133 Landslides ...................................................... ..............................................11
4.2.1 Location 3 .......................................................... ..............................................11
' 4.3 Traverse B-B' ....................................................................... ..............................................14
4.3.1 Location 4 .......................................................... ..............................................15
4.4 Traverse C-C' ...................................................................... ..............................................15
' 4.4.1 Location 5 ........................................................... .............................................15
4.4.2 Location 6 ........................................................... .............................................16
' 4.5 Traverse D-D' ....................................................................... .............................................17
4.5.1 Location 7 ........................................................... .............................................17
' 4.6 Traverse E-E' ........................................................................ .............................................19
4.7 Traverse F-F' ........................................................................ .............................................19
4.8 Traverse G-G' ....................................................................... .............................................19
4.8.1 Location 8 ........................................................... .............................................19
4.8.2 location 9 ........................................................... .............................................21
' 4.9 Traverse H-H' ....................................................................... .............................................23
4.10 Traverse I-I' .......................................................................... .............................................23
4.10.1 Location 10 ......................................................... .............................................23
4.11 Traverse J-J' ......................................................................... .............................................24
4.11.1 Location 11 .......................................................... ............................................25
'
4.12 Traverse K-K' ......................................................................... ............................................27
4.12.1 Location 12 .......................................................... ............................................27
4.13 Traverse L-L' ......................................................................... ............................................29
4.14 Traverse M-M' ....................................................................... ............................................29