Research tools and Information

This page has various tutorials and links about how to collect natural resource information. I'll periodically add more things as I come across them.



Montana Land Descriptions

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In Montana, to describe a location on most legal document there's a system of land descriptions used. These land descriptions are based on the Public Land Survey System (PLSS), a grid, that in Montana has an arbitrary axis just south of Three Forks, MT.

The grid is a cartesian coordinates system, referenced by Townships (Y) and Ranges (X). Everything north of the axis is described as a Township North, everything south of that axis is a Township South. Likewise everything East of the axis is a Range East, everything West is a Range West. The cells of that grid are called townships. One township is generally six miles by six miles square. For example: Township 15 North, Range 18 East is the 36 square mile area that Lewistown, MT sits in.

Townships and Sections

The illustration below is an example of one Township. The cells in blue, numbered from 1 to 36 are Sections within one Township. Most Townships have 36 sections. Sections are numbered from 1 to 36 in the order shown in the illustration. Section 1 is always in the North East corner of the Township while Section 36 is always in the South East corner and so on. Some townships have less than 36 sections; in that case they are numbered from 1 to how ever many sections are in the township in the same order.


Quarter Sections

One section is generally one square mile that contains 640 Acres. To specify an area within a section its divided into quarters. One quarter section is generally 160 Acres and 1/2 of a mile by 1/2 mile square. A quarter section can be divided into quarters again giving us four 40 Acre parts. If you divide those 40 acre parts into quarters again you get 10 acre parcels. Those 10 acre parcels are called a Quarter of a, Quarter of a, Quarter Section (NW, SW, SE of Section 25). The first quarter determines the 10 acre part, the next quarter determines the 40 acre part and the third quarter determines the 160 acre part. The section number determines the 640 acre part of a township.

Sometimes the smallest area is split into halves instead of quarters, this is refered to as a Half, Quarter, Quarter Section (N2, NW, NE of Section 36).


Certificate of Survey, Lot, Block and Subdivisions

In some areas that have been surveyed and subdivided an area will be identified by its Certificate of Survey (COS) and Tract number (TR). Often, properties that are within a Subdivision will be identified by Lot and Block followed by their subdivision name.

Montana Water Research Tools

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Here are some research tools that provide information that is otherwise hard to come by.

  • Printable Conversion Table of Commonly Used Units in Land and Water Management
  • Google Earth Layer of Controlled Ground Water Areas of Montana - This is an easy to use way to find if a location is with in a controlled ground water area. The file is usable in the free Google Earth Viewer. You must have Google Earth installed on your computer. By opening the file Google Earth is launched and it zooms to Montana and shows the controlled ground water areas on the map. You can then use Google Earth to search for a physical address or for a latitude & longitude like you would get from a GPS. It will show where that location is and you can see if it's in one of the controlled ground water areas.
  • Basin Query Page - This page produces the DNRC basin name and number by searching with a legal land description. The Montana DNRC uses these modified basins to categorize water rights throughout the State. Knowing the DNRC basin of a property can tell you at what stage of water right Adjudication that basin is in. It can also help with other types of water right research.
  • Stages of Adjudication:


    - "Yet to be Examined"

    - "Active Examination"

    - "Temporary preliminary decree" Issued in basins containing federal reserved
    water rights where a compact has not been concluded.

    - "Preliminary decree" The first decree issued in basins that don't contain any
    federal reserved rights.

    - "Final decree" After all objections have been resolved a final decree is issued.


    DNRC's Adjudication Status Page identifies the current status of each basin.


    Legal Chronology of Montana's Water Adjudication Process from the Montana Legislative Services Division


    How Will Completion of the Adjudication Affect Water Management in Montana? A very good report at Watersheds


    DNRC's Adjudication Information Site


    Surface Water Measurement

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    Surface water flows are highly variable through out the year and even year to year depending on snow pack, local precipitation and use.  For example, the table below is the mean monthly flows in the Clarks Fork of the Yellowstone River near Belfry, MT as recorded from a USGS gauging station.  Notice how the mean flow in June during the peak of spring runoff is almost twenty times the mean flow in February before the spring run off.


    USGS 06207500 Clarks Fork Yellowstone River near Belfry MT
    Monthly mean in cfs   (Calculation Period: 1921-08-01 to 2006-09-30)



























    This type of information is available at: USGS Water Resources of Montana


    There are many types of measure devices available ranging in accuracy, purpose and cost. So there are a few things to consider when selecting a measuring device. The Bureau of Reclamation Water Measurement Manual goes into the considerations in detail.These methods are widely accepted and used by professionals, but they may be excessive when something simpler or less expensive might due.

    Bureau of Reclamation Water Measurement Manual

    Chapter 4 - Selection of Water Measuring Devices


    Some of the common methods used for surface water measurement

  • Float Area Method is the most inexpensive way to measure the flow of a Ditch or Stream.

    Printable step by step instructions how to do the Float Area Method.


  • Trajectory Method can be used only when all the water is channeled through a pipe.
  • Weirs are installed in a stream or ditch and can be temporary or permanent

    Bureau of Reclamation Water Measurement Manual

    Chapter 7 - Weirs


  • Flumes are also installed in a stream or ditch and can be temporary or permanent

    Bureau of Reclamation Water Measurement Manual

    Chapter 8 - Flumes


    Ground Water Measurement

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    It’s important for land owners and water users to engage in pro-active ground water measurement of their wells and springs.  Climate changes, new water uses, changes in water uses commonly impact wells and spring in their vicinity.  With out accurate and credible documentation of ground water levels or spring flows it’s very difficult to quantify changes latter on down the road.

    Best Practices for Ground Water Measurement and Documentation

  • The exact location of the well or spring must be documented.
  • The best method is to take a GPS reading of the Latitude and Longitude.  Other options are to write down the legal land description to the quarter, quarter, quarter Section or at the very least to describe the location exactly so it can't be confused with any other spring or well.


  • Take monthly measurements for at least one year.
  • Spring flows and well levels fluctuate through out the year.  One measurement in June during a wet spring doesn’t mean much compared to a measurement in October after a dry summer.  Monthly measurements for at least one year and quarterly after that are very important to establish a credible baseline. Then after the first year take measurements at least every quarter or season.


  • Measurements must be made with generally accepted techniques.
  • Well levels should be recorded with something that does not stretch, a string doesn't work.  The best way is to use a commonly used device such as a Water Level Indicator or a Water Level Monitor.  Your Local Conservation Districts often have these devices on hand.  Some may be willing to loan the device and others will want to come out to your place to do the measurements.  Regardless of what device you use it’s important to document the technique, equipment and the date the measurement was taken.


    Water Line Water Level Indicators

    In-Situ Water Level Indicators

    In-Situ Water Level Monitor

    Springs can be measured with a stop watch and a bucket.  The best way to do this is to channel all of the spring into a pipe as close to where the water comes out of the ground as possible.  Then use a 1 gallon or 5 gallon bucket to catch all of the flow from the pipe.  Time how long it takes to fill the bucket and figure the flow out to gallons per minute.  If the flow is too great to be measured with a stopwatch and bucket other methods can be used such as the Trajectory Method, or you can install a Weir or Flume.


  • Make the measurements public before there’s a conflict.
  • It’s important to make your data public so that later there’s no question about it’s credibility. The Montana Ground-Water Information Center will archive your data for free and make it available on the internet for all to use.


    Remember, these measurements may in the worst case scenario need to stand up in court so be consistent, take pictures and clearly document how the measurements were taken.

    Research Links

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    Montana Topographic Map Finder

    An easy to use way to download and print USGS topographic maps as well as access to the Montana Natural Resource Information System.


    FEMA Flood Plain Maps access site

    This site allows users to select and print portions of the Flood Insurance Rate Maps called FIRMettes.


    Montana Clean Water Act Information Center
    This site has a searchable database of the Montana surface water quality TMDL information.


    Montana Ground-Water Information Center
    This site allows access to the Montana Bureau of Mines and Geology database that contains information from well logs and monitoring wells around the State.  Information on this site can be used to estimate ground water levels and aquifer recharge rates if a pump test is recorded.  Be sure to take into consideration the date of the well log or pump test as older data may not be as accurate today.  A user must create free login account to search the database. 


    DNRC Water Right Query System
    This page allows access to the DNRC water right database containing the location, flow, volume, source and owner names of all water rights searchable by several different criteria.


    NRIS Drought Website
    The Natural Resource Information System Drought advisory committee web site has a wide range of drought and climate information and maps.


    Montana State Reservoir Storage Reports 2004 to 2007

    This page has monthly reservoir volume measurements going back to 2004.


    USGS Water Resources of Montana
    This site allows access to the USGS gauging station and monitoring well data.  Many of the stations provide real time data but the site also provides records reaching back almost one hundred years.  Peak and mean annual, monthly and daily statistics can be searched.


    Montana Geographic Information Clearinghouse (NRIS)
    This site allows the user to search many sources of environmental, demographic and cultural information based on geographic locations such as a legal land description, county or watersheds.


    Montana Water Resources Survey Books by County
    These are PDFs of the original Water Resource Surveys of irrigated lands.  The surveys were conducted from the 40s to the 70s across the State.


    Bureau of Reclamation Water Measurement Manual

    Excellent manual of water measurement methods.


    USGS Ground Water Information Pages
    This site has several USGS publications about ground and surface water interaction and management.


    A list of references to estimate stream flows with out gauging data.
    These are some PDFs that describe how to estimate stream flows in different parts of the state where historical records do not exist.