The term "bench mark (BM)" refers to a 4-foot steel rod, 1/2 inch diameter, driven into the ground and protruding about 6 inches.
| Pin Number | Distance Along Line (ft) | Ground Slope (°) | Aug 13, 1963 | Aug 8, 1964 | Aug 3, 1965 | Aug 18, 1968 | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Distance from Line of Sight (in.) | Protrusion Above Ground Surface (in.) | Distance from Line of Sight (in.) | Protrusion Above Ground Surface (in.) | Distance from Line of Sight (in.) | Protrusion Above Ground Surface (in.) | Distance from Line of Sight (in.) | Protrusion Above Ground Surface (in.) | |||
| South Bench Mark | 0 | - | -(1) | - | - | - | - | - | - | - |
| 1 | 10 | 37 | 0.28 | 1.20 | 0.24 | 1.32 | 0.27 | 1.08 | 0.27 | 1.60 |
| 2 | 20 | 45 | 0.45 | 1.20 | 0.37 | 1.80 | 0.40 | 1.84 | missing | |
| 3 | 30 | 20 | -0.75 | 1.20 | -0.81 | 1.44 | -0.77 | 1.35 | -0.64 | 1.20 |
| 4 | 40 | 29 | -0.12 | 1.20 | -0.19 | 1.32 | -0.17 | 0.82 | missing | |
| 5 | 50 | 29 | -0.60 | 1.20 | -0.65 | 1.20 | -0.62 | 0.98 | -0.62 | 2.20 |
| 6 | 60 | 34 | -1.05 | 1.20 | -1.11 | 1.20 | -1.12 | 0.38 | -1.11 | 1.90 |
| 7 | 70 | 24 | -0.65 | 1.20 | -0.79 | 1.26 | -0.81 | 0.74 | -0.94 | 2.30 |
| 8 | 80 | 27 | -0.58 | 1.20 | -0.59 | 1.56 | -0.60 | 1.26 | -0.56 | 2.00 |
| 9 | 90 | 35 | -1.15 | 1.20 | -1.20 | 3.84 | -1.16 | 1.55 | -1.42 | 3.90 |
| North Bench Mark | 100 | - | - | - | - | - | - | - | - | - |
(1) Negative values are uphill of line of sight; positive values are downhill of line of sight.
Notes:
1. Line of sight bears N 25° E.
2. Set transit over south bench mark and sight to north bench mark
as close to ground surface as possible.
3. Angle from line of sight to tip of highest peak on Shiprock is
4°24' to the east.