Sumdum B-4, AK 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 Sumdum B-4 quad
The Sumdum B-4 quadrangle is a Forest Service FSTopo 7.5-minute map at 1:24,000 covering about 16 × 20 mi of Hoonah-Angoon (CA) and Petersburg, Alaska. It overlaps Tongass National Forest. The GeoPDF is 3.0 MB.
All Alaska Forest Service FSTopo maps · Alaska 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
14 named features inside the Sumdum B-4 — 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
Lakes, springs and falls
- Alice Lake · lake
- Farragut Lake · lake
- Little Lagoon · lake
- North Arm Port Houghton · bay
- Port Houghton · bay
- Salt Chuck · lake
- The Salt Chuck · lake
Gaps, arches and other landforms
- Rabbit Island · island
- The Haystack · cape
- Walter Island · island
Elevations are the USGS 3DEP ground elevation at the named point, rounded; a summit's surveyed height can differ a little.
More maps of Tongass National Forest.
Maps nearby
More maps around here ›
Sumdum B-4 SW, AK
Detailed map of terrain, trails and roads
USGS topo, 2021

Tongass National Forest
Forest Service forest map

Sumdum B-4 SE, AK
Detailed map of terrain, trails and roads
USGS topo, 2024

Sumdum B-4 NW, AK
Detailed map of terrain, trails and roads
USGS topo, 2021

Sumdum B-4 NE, AK
Detailed map of terrain, trails and roads
USGS topo, 2021

Sumdum B-3
Forest Service topo with road numbers
Forest Service FSTopo 7.5-minute quad
Version history
Version 1 · Nov 9, 2026 · 3.0 MB