CalTopo Layer Descriptions

In this article you will find descriptions of the layers offered in CalTopo. If none of the layers do what you need, consider building your own MapBuilder Layer (Pro users and above), or adding a Custom Source yourself.

Layer Description
Topographic Maps                            This set of maps is popular for outdoor recreation.
MapBuilder Topo
                                                                                                                                               
MapBuilder Topo is CalTopo’s signature layer. It is built from a variety of sources, updated quarterly, and is optimized for the outdoor recreationist. The MapBuilder Topo layer is designed to be responsive to zoom level and customizable: Pro level users and above can create their own customized MapBuilder Topo layers to highlight specific information, such as trails, property boundaries, or peak names that are important to the user.

Excels at: trip planning, especially when trips cover large areas. Displays well at multiple zoom levels, is clean and readable when printed, and is a great base map for overlays.

Limitations: In areas where few people visit the trails and some map data may not be as extensive or up to date. Consider a 7.5’ Scanned map instead.

Printable: Yes
View in App: Yes
Offline: Yes

MapBuilder Hybrid

                  
Map Builder topo with toned down NAIP imagery as the base.

Excels at: Viewing real world terrain characteristics with crowd-sourced overlay information; looking at trail alignments with regard to rocks and vegetation, focused on highlighting tree cover and clearings in relation to trails and contours

Limitations: may be less clear for printing.
Printable: Yes
View in App: Yes
Offline: No

Scanned Topos

   
7.5' quads assembled from Cal_Atlas scans and USGS GeoPDFs, plus a variety of other sources. Canadian maps come from NRCAN.
This baselayer is The Classic; The gold standard. Scanned 7.5 maps are very familiar for most outdoor recreationists. These maps feature excellent detail at close zoom levels. They are easy to read and familiar.

Excels atr: detailed trip planning, comfort and familiarity, details relevant to the outdoor rec user, look good. Can be useful in less traveled/more remote areas than MapBuilder Topo

Limitations: zooming out to see a larger area but while being able to see trails, text, etc. Therefore these can be more difficult for high level trip planning.

Printable: Yes
View in App: Yes
Offline: Yes

Forest Service

  
Forest Service road and trail layer assembled from FSTopo PDFs. The USFS (United States Forest Service) maps are only available for land areas owned by the USFS. They contain trails, campsites, and much other recreational information, but often lack continuity with surrounding land ownership types. For example, Yosemite NP will show up as blank white space while using these layers. As a solution you could layer the USFS maps over a MapBuilder or other baselayer to fill the holes.
Maps from 2016 with or without vegetation forest shading, as well as maps from 2013 are available. .

Excels at: recreation on USFS lands, historical trail alignments, cabins and ranger huts.

Limitations: Trips that exit boundaries of lands owned by the USFS need to be combined with another map type.
Printable: Yes
View in App: Yes
Offline: Yes

TF Outdoors

  
Thunderforest Outdoors describes their map as follows: Aimed at the outdoors enthusiasts, this map style displays hiking routes, ski runs and many useful points of interest.

Printable: Yes
View in App: Yes
Offline: No

Aerial Imagery                           
This set of maps is popular for outdoor recreation.

NAIP

 
1m resolution images from the National Agriculture Inventory Program imagery. Covers the CONUS only. These high-detail aerial layers are an excellent resource for the Continental US. The images are all taken in summer, and thus should not be limited by significant snow cover that would hide features or land types. We offer two sets of years (it takes several years to create each set of images across the whole country) in order to allow for different angles of light that may make a difference in the view. After selecting this layer, switch years by using the drop down menu that appears.

Excels at: understanding land cover and vegetation. Good resolution levels.

Limitations: only available for the CONUS.

Printable: Yes
View in App: Yes
Offline: Yes

False Color

 
A sub-option of NAIP, this is a False Color Infrared from NAIP 4-channel. It highlights vegetation.

Printable: Yes
View in App: Yes
Offline: No

Global Imagery

 
New as of September 2020, this layer contains aerial or satellite images for most of the land masses of the world.

Printable: Yes
View in App: Yes
Offline: No

Google Layers                           
Available on web only. No printing.

Google Street Map, Satellite, Terrain, Hybrid

 
Straight from the source, these layers are updated regularly. The satellite view is the highest resolution view available for aerial imagery in CalTopo. However, none of the Google layers can be printed or used in the CalTopo app. 20-30cm res in urban areas, 1.5m res in other areas.

Printable: No
View in App: No
Offline: No

Street Maps                           

MapBuilder Roads

 
This is a layer designed mostly for urban use.It highlights roads and paths, with little or no background noise from shading and vegetation, nor contours.

Printable: Yes
View in App: Yes
Offline: No

Open Street Map

 
Community sourced mapping project. From their site: OpenStreetMap is built by a community of mappers that contribute and maintain data about roads, trails, cafés, railway stations, and much more, all over the world. Updated quarterly. Data is open sourced. If you see a road or trail missing, contribute to OSM trails on the Open Street Map website (osm.org), following their guidelines.

Printable: Yes
View in App: Yes
Offline: No

Open Cycle Map

 
Cycling focused, community sourced maps. Topo and terrain shading added.

Printable: Yes
View in App: No
Offline: No

Shaded Relief                
Typically used in conjunction with other layers.

Normal

  
This is our rendering of the National Elevation Dataset with added vertical exaggeration. The resolution may vary depending on the source data.

Good for: using in conjunction with other layers to better visualize elevation changes and features; finding cool geomorphological artifacts such as old landslides or calderas; distinguishing man made features in natural terrain.

Limitations: This layer often works best as an enhancement to other layers, rather than alone for viewing typical map information, following a road or trail, or understanding vegetation.

Printable: Yes
View in App: Yes
Offline: Yes

Enhanced

 
This layer is designed to be used in conjunction with other layers, as a “stacked” layer.
Enhanced uses a server-side multiply blend on the other map layers, rather than an opacity based compositing. The map layers get darker, but you can crank it way up without washing them out.

Printable: Yes
View in App: Yes
Offline:

Terrain Shading

 
This layer is also designed to be used with another layer, as a “stacked” layer. In this rendition of the shaded relief data, the visualization is generated using a number of different light sources, rather a single 315 degree (NW) angle. Because of the multiple angles used, there is no “up” or “down”, and the map can be viewed from any angle without playing tricks on the eye. The downside is that in some areas it can be hard for the eye to quickly tell up from down.

Printable: Yes
View in App:
Offline:

Other Maps                  

FAA

 
Air paths, airports, and communications as per the US Federal Aviation Administration (FAA aeronautical charts)
A guide to this layer can be found at https://www.faa.gov/air_traffic/flight_info/aeronav/digital_product...

Printable: Yes
View in App: Yes
Offline: No

Historic Maps

                                                             
The historic maps can be a neat history lesson, or provide information about old mines and other features long-forgotten. Generally fun for exploring or useful for research, but not so helpful for navigation or current conditions.
Scanned Historical maps dating from 1885-1915. Maps in the 1915-1945 set may contain survey data from prior to 1915.

Printable: Yes
View in App: No
Offline: No

NPS

 
Now found in Map Sheets.

USFS Visitor

 
Now Found in Map Sheets.

Daily Satellites                

Weekly High Res (Sentinel)

  
The Sentinel-2 satellite covers the entire earth from the same viewing angle every 5 days with a 10m horizontal resolution. The date that the image was taken is displayed on the raw image - you may have to zoom out some to find this. We license this layer and don’t know precisely when the next image in your area will be taken, but it is within 5 days. You can “go back in time” on this layer to look at the image from approximately a week before, or various set intervals in the past back several years.

Good for: establishing semi-current conditions, particularly for snow cover.

Limitations: currently affected by cloud cover (though there may be a way around this soon, not meant to be quite the level of detail as Google (at 20-150 cm resolution) or NAIP (at 1m resolution) images

Printable: Yes
View in App: Yes
Offline: No

Daily

  
These low resolution layers are best viewed at a wide zoom level and help you to identify major terrain features and transitions. You can go back in time for a number of intervals on this layer.
Choose from a drop down list to access different satellites.
The Aqua (2002) and Terra (1999) satellites each carry MODIS instruments to record infrared and visual imagery of the earth with a 250m resolution. The VIIRS instrument aboard the Suomi NPP spacecraft (2011) records daily images also, with a slightly less detailed resolution range of 375m.

Excels at: Viewing daily regional information, and comparing to previous days. Could be helpful for viewing changes in large area snow cover from one day to the next, checking the cloud cover for a person that went missing X number of days ago, or greening up of an area through the days after a rain, or viewing a burn scar after a fire. Also good for long-distance planning, but not specifics on the ground.

Limitations: Washes out as you zoom in. Affected by cloud cover.

Printable: Yes
View in App: Yes
Offline: No

Nightly

  
Low resolution layer best viewed from a wide zoom level. These low resolution layers are best viewed at a wide zoom level and help you to identify major terrain features and transitions. You can go back in time for a number of intervals on this layer.

Limitations: Washes out at mid and high zoom levels.
Affected by cloud cover.

Printable: Yes
View in App: Yes
Offline: No

Below are links to some blog articles related to CalTopo Layers: