| Percent of plots infested | ||||
| Ridge | Slope | Bottom | Location | Reference |
|---|---|---|---|---|
| 67 | 53 | 37 | Mescalero Apache Indian Reservation | Hawksworth 1959a |
| 57 | 36 | 16 | Arizona and New Mexico | Andrews and Daniels 1960 |
| 42 | 33 | 0 | Colorado | Merrill and others 1987 |
| Note: 2,464 plots were examined on Mescalero Apache Indian Reservation, 2,164 plots in Arizona and New Mexico survey, and 547 plots on Colorado survey. | ||||