Porphyry Reef, MT Forest Service Topo Map (FSTopo)
by Forest Service FSTopo Quads (public domain), US
A free GeoPDF for offline GPS in the Cartahaven app, with free updates. How it works offline
About the Porphyry Reef quad
The Porphyry Reef quadrangle is a Forest Service FSTopo 7.5-minute map at 1:24,000 covering about 7.3 × 9.8 mi of Flathead and Teton counties, Montana. It overlaps Flathead National Forest and Helena-Lewis and Clark National Forest. The GeoPDF is 1.3 MB.
All Montana Forest Service FSTopo maps · Montana hunting units
What you get
- Your GPS position on the map. A blue dot on this official sheet shows where you are.
- Works with no signal. Download it once; the map and your GPS position keep working with no cell signal.
- Tracks, placemarks and photos. Record where you go, drop pins, and export GPX, KML or GeoJSON.
- Free updates. When a new edition is published here, it’s yours at no cost.
- 1Tap “Get this map”: it’s added to your free account.
- 2Open the Cartahaven app on your phone and sign in.
- 3Tap “Get my maps”. It’s on your phone, ready offline.
The app runs on iPhone, Android and in desktop browsers. Install it · How offline GPS works
Where this map covers
Named places on this map
13 named features inside the Porphyry Reef — Forest Service FSTopo 7.5-minute quad sheet, from the USGS Geographic Names Information System. Each one links to every map that shows it.
Peaks and ridges
- Bowl Mountain
- Mount May
- Porphyry Reef · ridge
- Wapiti Ridge · ridge
- Washboard Reef · ridge
- Wrong Ridge · ridge
Gaps, arches and other landforms
- Grimsley Park · flat
- Grizzly Park · flat
- McDonald Park · flat
- Ninemile Park · flat
- Round Park · flat
- Sun River Pass · gap
- Teton Pass · gap
Elevations are the USGS 3DEP ground elevation at the named point, rounded; a summit's surveyed height can differ a little.
More maps of Flathead National Forest and Helena-Lewis and Clark National Forest.
Maps nearby
More maps around here ›
Porphyry Reef, MT
Detailed map of terrain, trails and roads
USGS topo, 2024
Teton River Area Over-Snow Vehicle Use Map (sheet)
Where snowmobiles are allowed
Helena-Lewis and Clark National Forest (2019)
Rocky Mountain Ranger District Over-Snow Vehicle Use Map
Where snowmobiles are allowed
Helena-Lewis and Clark National Forest (2019)
Choteau 30x60 Land Ownership (BLM Surface Management)
Land Ownership Maps from BLM Data · Montana
Helena-Lewis and Clark National Forest
West — Forest Service forest map
Flathead National Forest
Forest Service forest map
Version history
Version 1 · Nov 8, 2026 · 1.3 MB