# GPS on GIS / Am I on the property line?



## head (Feb 13, 2004)

We have an opportunity to build trails on municipal property surrounded by private property and want to make sure we take full advantage of the municipal land w/o overstepping any bounds. Being able to walk through the woods and see where I am on a tax map would rule.

Is there any app (hopefully free or cheap) that allows for the overlay of current location per GPS onto a GIS tax map?


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## Cotharyus (Jun 21, 2012)

Yes. Also, many newer hand held Garmin units support custom mapping, which allows the same sort of functionality. I know little enough about the GIS app side that I'll leave making a recommendation on that to someone else - but be aware many Garmin units can do what you need by allowing you to import the tax map.


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## 2bfluid (Aug 17, 2008)

A lot of counties have GIS departments and free applications to view deeds. You can also go retro and go to the court house and visit the register of deeds and get the deed and or plats. 

You can also hit up a local surveyor to volunteer to locate and flag the pins or property lines. Usually you can find the old cut lines/fence lines with some home work and logic.


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## head (Feb 13, 2004)

well that's promising. anyone here have experience with Garmin's with this capability? suggested models? things to look out for (do buy/don't buy)?

i'd really like to find an app that'll work on a phone in order to avoid an equipment purchase but if a new garmin is the only way then i'll see how much it would hurt the bank account.


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## head (Feb 13, 2004)

i have no problem viewing the tax maps on the county GIS site. what i need to be able to do is walk out into the woods and know if i'm on the line or not.


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## iceboxsteve (Feb 22, 2012)

In all honesty if crossing property lines is that important I wouldn't rely on GPS or GIS. As an engineer/surveyor an on the ground survey is the way to go when having to establish property lines. I rarely survey with GPS (thats survey standard GPS) unless its wide open and clear.

Granted I understand the financials of this, survey is not cheap. Are the bounds marked? You could always "rough in" the line by trying to flag between the corners, if you can find them (and you'lll be assuming they are actually in the right location).


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## JDM (May 2, 2008)

I also recommend walking the boundaries with a survey before starting to scout for trails. Don't forget to bring a compass. You should also bring you GPS along to record the corners to help with future mapping.

You may wish to flag the boundaries. We put up blue flags for the boundaries and use orange or pink to flag trails.


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## 2bfluid (Aug 17, 2008)

Look for chest high cut marks on the trees adjacent/pointing to the line. If you find three cuts on the same tree, the three wise men, they are pointing to a corner. You can also look for old signs of surveyors. Most if not all public land has been surveyed. Look for branches and small trees that have been cut from chest high to the ground. Fences are usually just off the line. 

See if the LM staffer has any knowledge of the boundaries in the area of question. 


Most common GIS units are only good to 50'. 

If there is a nice homeowner or old timer they can also help, but it may be better to let those sleeping dogs sleep.


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## kubikeman (Jun 4, 2010)

Don't ever completely trust county GIS tax maps. Unless the property boundary has been verified recently, it's most likely wrong. Also, anything handheld (cell phone, cheap Garmin... etc.) is going to have a large amount of positional error. I would avoid getting too close to the property boundaries if it's going to be an issue. Maybe approach the surrounding land owners and ask if they could show you their property. They might know where lines and pins are.

Many of the newer Garmin units can read KML. You can actually take a scanned tax map and georeference it on Google Earth. From there you can export the layer as a KML and load it onto your GPS unit. Bare in mind you loose accuracy all the way in this process.

Bottom line, you can use the above suggestions to get some idea of the property boundary, but if you plan on developing the property for public use, you may want to get professional help. Put the word out, you never know. You may find someone who works for an engineering firm with access to the right tools who also rides


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## head (Feb 13, 2004)

This is all good advice and we will certainly want to get precise in the near future, but for the purpose of an initial walkaround, it would be nice to have a quick-n-dirty way of establishing who's land we're on. So going back to the original question, can somebody recommend an app (if it exists) and/or specific Garmin models that will satisfy that need?


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## kubikeman (Jun 4, 2010)

You can get the base model Garmin GPS 62 on Amazon for $200. It seems to be the lowest level Garmin that supports custom maps. Keep in mind with Garmin, the price difference in models comes from additional features like cameras and basemaps. Basemaps you can buy separate and their cameras suck, so I would go with the base model on any one you choose.

Amazon.com: Garmin GPSMAP 62 Handheld GPS Navigator: GPS & Navigation

A good app is Backcountry Navigator Pro ($9.99 android only).

Again, please keep in mind after georeferencing tax maps and loading them on a device like these you could be looking at 20 - 50 foot accuracy in best conditions. You could encounter 100+ foot inaccuracy if you have heavy canopy cover and the tax maps are really off.

GPS works off line of sight, so the steeper the terrain, the time of day and canopy cover can all work with you or against you.


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## evasive (Feb 18, 2005)

With all the caveats offered above in mind...

Yes, there are some smartphone apps that do this, but you may or may not be able to find data for your area, or an app that runs on your operating system. Search your app market for "cadastral." 

You can also find free cadastral data for most consumer grade GPS units, too. I use it on my Garmin as a quick reference when out doing field work. But to circle back, I wouldn't trust it for more than that.


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## 2bfluid (Aug 17, 2008)

Some paper, logic, and common sense may be your best app. Its not that hard (usually) and they are almost always straight lines. 

Good luck


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## kubikeman (Jun 4, 2010)

Property deeds are public record and you can pull them at your local courthouse. You should be able to obtain a deed plot of the municipal property you're looking to develop.


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## formica (Jul 4, 2004)

We had student volunteers from the local community college's forest department do our survey. They used the super powerful professional units ( forget the name) and did it for one of their classes. I am friends with one of the instructors so it was easy to set up. If your local school has anything like that, they are usually looking for projects for the students.


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## BonkedAgain (Aug 23, 2005)

Orux Maps (Android freeware) has the ability to overlay a KML based map in its display. I haven't tried it myself but given the price it's worth giving it a shot. OruxMaps

For scouting purposes I think a phone is very handy. If you have lots of room and don't think you will need to get to less than, say, ~200' of a property boundary then it may be good enough. Otherwise, I agree with everybody else, you will need to get a professional surveyor in there to determine the actual property lines.


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## kubikeman (Jun 4, 2010)

2bfluid said:


> Some paper, logic, and common sense may be your best app. Its not that hard (usually) and they are almost always straight lines.
> 
> Good luck


Oh yeah?  That boundary is not a stream or a road.









Sorry, couldn't help myself. It's a slow day at the office.


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## Jelf (Jun 26, 2010)

head said:


> This is all good advice and we will certainly want to get precise in the near future, but for the purpose of an initial walkaround, it would be nice to have a quick-n-dirty way of establishing who's land we're on. So going back to the original question, can somebody recommend an app (if it exists) and/or specific Garmin models that will satisfy that need?


I own the startup http://www.PropertyLineMaps.com and *volunteer to do what you want pro bono. *

Is there cell phone coverage on this land? If so, I will produce a link that you can open with the browser on your phone. That link will:

1. Start the free *Gmap4* enhanced Google map viewer I developed
and
2. *Display the approximate boundary of the municipal land
*
As you walk around on the land you will be able to change the basemap from the Google aerial to a *hi-res topo*.

Depending on the location, I might be able to include *aerials* that are more detailed than Google's.

Gmap4 includes a *geolocation* feature that will center the map where you are standing. Menu ==> My location.

I will also give you a *GPX file* that has the approximate municipal boundary. If any of your colleagues has a GPS then they can use that GPX file to load waypoints into their GPS for the approximate property corners.

Please use the contact page on my website to send me details about the land so I can locate it.

Joseph Elfelt
Redmond, WA


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## JDM (May 2, 2008)

head said:


> This is all good advice and we will certainly want to get precise in the near future, but for the purpose of an initial walkaround, it would be nice to have a quick-n-dirty way of establishing who's land we're on. So going back to the original question, can somebody recommend an app (if it exists) and/or specific Garmin models that will satisfy that need?


Maprika (free) for iPhone or android would work well if you have some type of map image available. If the map is to scale then you jet need a few point that you can reference to the satellite imagery. The accuracy should be sufficient for your initial scouting that you want to do.

You will probably want to reference your map with the PC version.

MAPRIKA - Make your own map

I just started using this tool so I can see my current location on MY map while I'm out scouting.


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## drew p (Jan 20, 2012)

Check out PDFmaps by Avenza. Shows where you are on any georeferenced PDF and you can track, add waypoints, etc. Easy to make a map with ArcMap, your municipality can probably get one for you.


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## bsieb (Aug 23, 2003)

Backwoods Navigator Pro can download and display a lot of maps, I use it to locate private property boundaries in national forest. Android only.


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## Harold (Dec 23, 2003)

Every situation I've needed this information, the property lines have had at least old fences. I've had to stay a minimum distance from that stuff.

If no such features were available, I'd have the land manager walk it with me first so I had a general idea. If I needed more detail, then I'd be looking at surveys.

SOMETIMES, municipal, county, state, or federal agency websites provide GIS data for their property boundaries.

It's usually in Shapefile format, and you should be able to use GPSBabel or one of a few other programs to convert it to .gpx. Once there, you can use GPX2IMG to make a transparent basemap for ANY mapping-capable Garmin. these should be fine for "general reference" type information to at least get you looking in the right area for on-the-ground features indicating a property line (fences, survey markers, etc). When you find the spot on the ground, you can set a Garmin handheld GPS to record a waypoint, and average the points for several minutes. I've done this for my own property, and while it may not be accurate enough for a survey crew, it's been plenty accurate for my own purposes. I did this so I could georeference the survey plat for my property and it was within a foot or two.


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## smeets1 (Dec 30, 2003)

iceboxsteve said:


> In all honesty if crossing property lines is that important I wouldn't rely on GPS or GIS. As an engineer/surveyor an on the ground survey is the way to go when having to establish property lines. I rarely survey with GPS (thats survey standard GPS) unless its wide open and clear.


+1

If you truly need to know the property line, a survey is the only way to go.


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## bsieb (Aug 23, 2003)

^While technically true, usually you just want to stay well on your side of the boundary. If inches matter, a survey may not help, the corners will be located but you will still have to guess at what is between, depending on terrain. We try to stay at least 100' from property boundaries even if there is a fence or USGS marker present.


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## Jelf (Jun 26, 2010)

The OP's request is a great example of someone that has a legitimate reason for wanting to get information showing approximate property lines but who does not, at the present time, require survey grade accuracy. Perhaps there will come a time when some or all of this land is surveyed but that very large expense is simply not needed in the early planning stages.

Surveyors provide an essential function and I have certainly purchased surveys a number of times for different property that I have owned. However, it has also been said the "[p]erfection is the enemy of good enough". And in many cases, knowing approximately where the property corners and lines are is good enough for the purpose at hand.

I got a PM from Head with the details about the property he wants to check out for trail potential. *The following link starts Gmap4 and displays the approximate property lines on the Google aerial. * This link is actually over a dozen lines long since the link itself holds all the coordinate data for the property lines. Think of this as a *"map-in-a-link"*.

http://www.mappingsupport.com/p/gma...?name=1_ft_imagery&layers=2&transparent=false

The approximate property lines you see are based on data from the county GIS. Some of this data is not as good as we would like. For example, the line from point 14 to 18 likely needs to be shifted to the east. If any of this property or the adjoining land has already been surveyed, then I can increase the accuracy of the map.

To see the hi-res topo switch the basemap to *"t4 Topo High"*. Also, you might want to go to the end of the list of basemaps and check out the *"1_ft_imagery"*. Those aerials are hosted on a federal GIS server.

To turn the corner labels off do Menu ==> Labels on/off.

To use the Google Earth browser plugin and *fly over the property smoothly in 3D*:
1. Select the "Earth" basemap. You will see a window with some text. 
2. Either press "Continue" or install the plugin.
3. Tilt the map back more by holding shift + left mouse button and dragging the mouse toward you.
4. *Here's the fun part. *Now put the cursor on or a bit above this land. Hold the right mouse button down and slowly move the mouse this way and that. This control lets you zoom in/out while also rotating the map.

For the best 3D effect you need to tilt the map a bunch.
Note also that the vertical height difference is exaggerated.

*Of course you can also view your own GPX/KML/KMZ/TPO files with Gmap4 and fly over them in 3D.*

Joseph, the Gmap4 guy


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## Cotharyus (Jun 21, 2012)

That's a really cool map. But more than anything else, when I look at this map...

I figure that's a bit of land off I95 in Northern Va. Being from not-so-far from there originally, I'm reminded how awesome some of the properties in that area really are. That's a nice piece of land. Around here (middle TN), we get 100 acres to build trail on and we lose our minds. Oh for 600-1000 acres....


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## hado_pv (May 26, 2006)

I'll second Maprika, and the newer smart phones that use the Russian GPS Sat's as well as the US ones add accuracy that the base Garmins lack. The problem is, in our area, most tax maps are free-hand drawn, then converted to GIS, not based on surveys, so the overlays get pretty comical at times.


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## head (Feb 13, 2004)

Thanks for all the advice folks. I picked up a Garmin 62 and loaded the map made by Joseph with his Gmap4. It worked great! 

The property line was pretty easy to find on one side of the parcel since it is essentially the road (minus easement). From that point forward the line was easy to follow with the GPS but would not have been easy without it. Following Josephs map took us right to some old boundry markers, survey tape, fencelines and access roads. We may have been able to piece together an idea of the line from those landmarks without this map (had we found them) but with the map and a GPS?... cake. a buddy was using his phone and oryx maps, having good success too but i think he had to keep hitting refresh to check location. maybe not a big deal. regardless, Joseph's map seemed to be spot-on and his support was phenomenal.

cheers!


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## MitchC (Mar 21, 2016)

Why not use an app like MyLand?

https://play.google.com/store/apps/details?id=com.land.my.mylandpro


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## BonkedAgain (Aug 23, 2005)

MitchC said:


> Why not use an app like MyLand?


Umm, because it has no track record and its description makes it sound like it is a useless piece of software. It sounds like I can do all that and more using most existing navigation apps.


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## bigskyguy (Apr 6, 2008)

Works great for hunting on public and private land. 
https://www.huntinggpsmaps.com/


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