About and Contact

Read Summary
Close Summary

Find me on social media at:
Mastodon - https://m.ai6yr.org/@mappingsupport
Facebook - https://www.facebook.com/GISsurfer/
YouTube - https://www.youtube.com/@mappingsupport/videos

My name is Joseph Elfelt and I am a software developer in the field of web maps living near Redmond, Washington, USA. In the past I have been a programmer for Boeing working with database technology and also spent many years as a real estate investor. Those two skill sets have been combined into a one-of-a-kind consulting service I offer producing interactive property line maps for clients. If you need to find existing survey stakes or approximate property lines, then please take a look at this service to see what I can do for you.

In addition, I also produce several map-related public service projects that are part of my way to "pay it forward". If you like maps, check out GISsurfer which is a general purpose web map based on the free open-source Leaflet map API (Application Program Interface). In addition to the standard web map features, GISsurfer lets anyone 'surf' ArcGIS data almost as easily as you surf the internet. No GIS savvy required! Whatever you are interesting in, if it is related to a location on the earth then there likely are data layers on an ArcGIS server that you would enjoy seeing on a map.

Another new project under development is GeoJPG which is a new kind of web map. First, GeoJPG is a Progressive Web App (PWA) which means it can be installed and will work offline in the user's browser. Second, it displays georeferenced JPG images. Those JPGs can be created with GISsurfer which has a new feature that lets the user take a series of georeferenced screenshots that exactly adjoin.

Another public service project of mine is curating a PDF file which has 3,000+ ArcGIS server addresses. These are public-facing (i.e. no login required) USA-based government servers from the federal level down to the local level. All address links are scanned by my code once per week and any bad links are either fixed or flagged.

Now think about calling 911 with your cell phone. A few years ago I read a news story about the difficulties that 911 call centers have sometimes in locating wireless callers. As a result I wrote FindMeSAR which is a simple web page that displays the user's coordinates and accuracy value. The yellow screen displays your coordinates in the format used by all 911 call centers in the USA. FindMeSAR is a Progressive Web App (PWA) which means it can be installed and will work offline.

For more information about my property line consulting service or any of my public service projects you can click the appropriate button below.

Close Summary


Read Summary
Close Summary

If you find any of my projects to be especially useful to you, please consider making a donation. You can use your credit card to donate through PayPal. You do not need a PayPal account. Click the 'donate' button below to go to PayPal.

Thinking of making a donation but you would like something more in return?

Please take a look at my commercial service producing online maps that show approximate property lines. Clients email me either a land survey or the legal description of their land as shown on their deed. I process that data with first-of-its-kind software I developed and send back a link that opens an online map that displays a high resolution aerial and the client’s approximate property lines. The client can turn on a geolocation feature that shows where they are as they walk around. Each client also receives a GPX file that can be loaded into many Garmin GPS units.

This service produces the most accurate corner coordinates possible without hiring a surveyor. You can use the online map and data this service provides to find 'lost' survey stakes, market your property, hunt on your side of the line or locate the approximate corners of unsurveyed land.

For more information on this service please see:
Mobile users - FindPropertyLines.com
Non-mobile users - PropertyLineMaps.com

Thank you for your support! It is greatly appreciated.

Close Summary

GeoJPG version 2
Offline Maps

Read Summary
Close Summary

The GeoJPG ‘web app’ lets you view your own custom maps offline on both iOS and Android devices with NO ads, NO tracking, NO signup and NO fees.

I developed the GeoJPG web app as a public service and part of my way to ‘pay it forward’. This is not a commercial product of any nature. I am making this freely available simply because I can.

Website: https://geojpg.com

Web App: https://geojpg.com/geojpg.html

For a PDF with some screenshots see:

For a PDF with with an overview and some background see:

Close Summary

Property Line Maps

Read Summary
Website - Cell Phone
Website - Desktop
Close Summary

This is a consulting service that produces the most accurate property corner coordinates you can get without buying a survey. Clients email me information about their property. I process that information with software I developed and produce a custom map that displays the client's approximate property lines and corner locations on an aerial basemap.

These custom maps are more accurate than the county parcel line data that you can see with apps from LandGlide, Regrid, onX and others. To learn more about problems with county parcel line data, open either website shown below and read the FAQ.

Clients can open their custom map with a smartphone or tablet and then turn on a geolocation feature that will show where they are as they walk around. When geolocation is turned 'on' the GPS accuracy value is displayed and constantly updated. The map can work either online or offline on both iOS and Android devices.

Common uses for this service include finding 'lost' survey stakes, marketing property that is for sale, making a good faith effort to hunt only on your own land, locating the approximate corners of unsurveyed land, etc.

If you are using the map online then contour lines can be displayed on top of the aerial and you can change the basemap to the USGS topographic map.

Please keep in mind that the corner coordinates and property line data this service produces are approximate and are not a survey. If you need to know exactly where your property lines are located please contact a surveyor.

For more information about this service please see:
Mobile users - FindPropertyLines.com
Non-mobile users - PropertyLineMaps.com

Close Summary

Wildland Fire Maps

Read Summary
Close Summary

For a number of years I have volunteered to produced interactive maps of wildland fires. These maps are displayed by GISsurfer and feature a number of GIS overlays that the user can turn on/off. Each map always includes the latest MODIS and VIIRS satellite hotspot data. Often for larger fires there is a nighttime infrared overflight. My map uses that data to display the most recent fire perimeter and areas where the fire is burning intensely.

Each map has two links in the upper left corner to help you get the most benefit from the map.

The best place to see these wildland fire maps is the MappingSupport twitter feed:

Close Summary

3,000+ Government ArcGIS Servers

Read Summary
Close Summary

Here is a PDF file with a list that I curate of 3,000+ addresses for government ArcGIS servers. These servers range from the federal level down to the city level. GISsurfer can display data that is hosted on these servers.

Everyone is welcome to share this list. The list is automatically scanned once per week by my own code to ensure that dead links are promptly fixed or flagged. An updated list is usually posted each Wednesday morning.


There is a nice article about this work in the URISA national newsletter. This is an organization of GIS professionals. See page 12.

You do not need to be a GIS professional to benefit from this list of ArcGIS server addresses. Here is a PDF I prepared with step-by-step instructions showing how data can be downloaded from an ArcGIS server and saved as a KMZ file that can be used with ATAK, ITAK, Google Earth and various other programs.

Close Summary

A General Purpose Web Map

Read Summary
Close Summary

GISsurfer is a general purpose web map based on the free open-source Leaflet map API (Application Program Interface). It will work on most devices that have a browser. Depending on your device, you will see either a touch-friendly interface or mouse-oriented interface. An easy way to see the various features is to click the 'Menu' button or basemap button and then try the various choices.

In addition to the standard web map features (search, geolocation, save a custom map link and multiple basemaps) GISsurfer has a big impact feature you are unlikely to see on any other web map. You can open GISsurfer and then view data that is hosted on thousands of public-facing (i.e. no login required) GIS (Geographic Information System) servers. No GIS savvy required! You can split the screen and display the table of contents of an ArcGIS server on the left side with the map on the right side. Drill down on the table of contents to a data layer, click the layer and in a few seconds that data appears on the map. Click layer - See data. For more information please visit the GISsurfer homepage (see link below) and click Menu ==> Help and scroll down a short way to the section listing several PDF files.

This link takes you to the GISsurfer homepage.
https://gissurfer.com (You will be redirected)

The following link starts GISsurfer and displays the default map.

Close Summary

New in 2023
GISsurfer Tutorial Videos

Read Summary
Close Summary

For links to the tutorial videos, open the GISsurfer homepage (https://gissurfer.com), click the green 'Menu' button and go to the Help page.

Close Summary

GISsurfer Special Maps

Read Summary
Close Summary

In addition to opening GISsurfer and then 'surfing' data that is hosted on GIS servers, you can also make GISsurfer map links with pre-defined GIS overlay layers that can be turned on/off and restacked on the map. Below are links to a few GISsurfer maps that I made. Most of these maps have well over a dozen data overlay layers that you turn on/off and restack. These GIS maps do not display a static file where the data never changes. Instead, each time you open one of these maps or turn on a data overlay layer, the most recent data flows from the GIS server to your screen.

If you click the "Map Tips" link in the upper left corner of a GIS map then you can quickly learn how to (1) turn other GIS overlays on/off, (2) how to display GIS attribute data for the overlay that is "on top", (3) how to make your own custom map link so the map opens the way you want it to look and more useful tips. Also the map legend is usually part of the "Map Tips" page.

Each of these map links includes a txtfile parameter that points to a txt file that I made. The pre-defined GIS layers the map can display are defined in that txt file. If you are curious to see what that looks like, simply copy the address for any of those txtfiles and paste it into a browser.

In order to learn how to turn GIS overlay layers on/off and get the most benefit from the map, please take a few minutes to open any map and read the "Map tips".

Private Parcel and Public Land Map

This map can display private parcel lines for 26 states. It can also display a wide variety of public land from federal to local. After the map opens please click "Map tips" in the upper left corner and read the disclaimer so you understand the limitations of the parcel data. The tips section "About the data" also has important information about the parcel data.

Detailed Recreation Maps

National Forest Recreation Map
There are GIS overlay layers that show trails, roads, campgrounds and much more.

Bureau of Land Management Recreation Map
This map is zoomed in on an area in Colorado when it opens, but it covers all BLM land.

National Park Recreation Maps
There is now a separate GISsurfer map link for each of the 63 national parks. When you open any of these maps the trails are highlited and will be easy to see on any basemap. You can find these map links on this web page:

NOAA Nautical Charts Map

Disaster Maps

Weather Map

Wildland Fire Map

For some of the larger fires I also produce a daily map that shows the latest fire perimeter. This perimeter data is produced by fire staff that analyze infrared data collected by a nighttime overflight. The best place to see those map links is the MappingSupport Twitter feed

Close Summary


Read Summary
Close Summary

If you want to see online gridded maps, GISsurfer can help you do so. Three kinds of gridded maps can be displayed.

GISsurfer map with MGRS (Military Grid Reference System) grid

GISsurfer map with USNG (U.S. National Grid) grid

GISsurfer map with UTM (Universal Transverse Mercator) grid

Close Summary


Read Summary
Close Summary

Special note for iOS 17.1.1
FindMeSAR might not work due to a bug in this version of iOS. That bug has been fixed in the beta version of iOS 17.2.

FindMeSAR (https://findmesar.com) is a web page that uses the GPS chip in your device to display your coordinates and accuracy value. The "Next Format" button will scroll through five coordinate formats. Each one has a different colored screen.

I volunteered to develop this 'web app' (aka Progressive Web App - PWA) as a public service after seeing news stories of people that called 911 and there was confusion over their location. Some people died as a result of that confusion.

If you ever need to call 911 then use the yellow screen to provide your coordinates in decimal degrees and the accuracy value.

When you open FindMeSAR you will see instructions showing how to install it for offline use. There is a Tips button with more information.

FindMeSAR is not available in any app store. The only way to install it for offline use is to carefully follow the instructions you see when you open it.

Close Summary

Calling 911 With a Cell Phone
Tips That Might Save Your Life

Read Summary
Close Summary

Big picture most important take home point:
The basic 911 system *does not* make any use of coordinates produced by cell phones. Instead, the 911 system uses coordinates that are intentionally dumbed down and less accurate than the coordinates produced by cell phones. In short, Uber uses more accurate coordinates to give you a ride than 911 uses to try and save your life.

These tips for calling 911 with a cell phone were developed in part after an extensive review of documents on the FCC website. In addition, input was received by people working in the telcom industry.

Among other things you will learn why it is important to try calling 911 even if your phone says 'no service' and why everyone needs an app on their phone that will display their coordinates and the equally important accuracy value.

The last page of this report has links to several related reports. One of them explains why sometimes 911 cannot determine the location of a cell phone unless the caller provides that information. This weakness in the 911 system is the reason why everyone needs some way to use their cell phone to display their coordinates and the equally important accuracy value.

The tips are in this PDF file:

Close Summary

Tips for ATAK and WinTAK

Read Summary
Close Summary

ATAK is an android app for situational awareness and is gaining use by first responders including for wildland fires. Among the features of ATAK is the fact that it is funded by the federal government and free for any USA citizen to use. For more information see https://www.civtak.org/atak-about/

The iOS version (iTAK)and windows version (WinTAK)are also free but do not have as many features as ATAK.

A vast amount of GIS data can be displayed by ATAK and WinTAK without the need for any plug-in. For a series of PDF files with step-by-step instructions and plenty of examples see:

Close Summary