| Porcupine Ridge | |
| Elevation Ft: | 9128 |
| Elevation Ref: | [1] |
| Prominence Ft: | 1688 |
| Isolation Mi: | 1.57 |
| Isolation Ref: | [2] |
| Parent Peak: | The Guardhouse (9,341 feet) |
| Part Type: | Protected area |
| Part: | Glacier National Park |
| Country: | United States |
| State: | Montana |
| Region: | Glacier |
| Region Type: | County |
| Map: | Montana#USA |
| Label Position: | bottom |
| Range: | Livingston Range Rocky Mountains |
| Coordinates: | 48.92°N -113.9832°W |
| Topo: | USGS Porcupine Ridge |
| Rock: | Sedimentary rock |
| Age: | Precambrian |
Porcupine Ridge is a prominent mountain ridge located in the Goat Haunt area of Glacier National Park, in Glacier County of the U.S. state of Montana.[3] This mountain is part of the Livingston Range, and is situated 1.5 mile east of the Continental Divide. Topographic relief is significant as the summit rises approximately 3900abbr=offNaNabbr=off above Lake Frances in one mile, and nearly 5000abbr=offNaNabbr=off above Waterton Lake in five miles. Precipitation runoff from the mountain drains to the Waterton River via Olson and Valentine Creeks. This geographical feature's name was officially adopted in 1911 by the United States Board on Geographic Names.[3]
Based on the Köppen climate classification, Porcupine Ridge is located in an alpine subarctic climate zone characterized by long, usually very cold winters, and short, cool to mild summers.[4] Winter temperatures can drop below −10 °F with wind chill factors below −20 °F. This climate supports the remnant of an unnamed glacier on the northeast aspect below the summit.[5]
Like the mountains in Glacier National Park, Porcupine Ridge is composed of sedimentary rock laid down during the Precambrian to Jurassic periods. Formed in shallow seas, this sedimentary rock was initially uplifted beginning 170 million years ago when the Lewis Overthrust fault pushed an enormous slab of precambrian rocks 31NaN1 thick, 50miles wide and 160miles long over younger rock of the cretaceous period.[6]