NAD83(2011) / RMTCRS Flathead 83 (ft)

Puerto Rico , accuracy 2.0 m, code 9774 (default) [3]

Selected transformation

Name: NAD83(2011) to WGS 84 (1)

Method: Geocentric translations (geog2D domain)

Remarks: For many purposes NAD83(2011) can be considered to be coincident with WGS 84. This approximation ignores the ~2.2m offset of NAD83 from the geocentre, the low accuracy of the WGS 84 ensemble and the application of tectonic plate motion to WGS 84 data.

Information source: IOGP

Revision date: 2021-09-08

Attributes

Unit: foot

Geodetic CRS: NAD83(2011)

Datum: NAD83 (National Spatial Reference System 2011)

Ellipsoid: GRS 1980

Prime meridian: Greenwich

Data source: EPSG

Information source: Rocky Mountain Tribal Transportation Association RMTCRS Handbook and User Guide; https://www.marls.com/wp-content/uploads/2025/10/RMCRS-Manual-v2.0.pdf

Revision date: 2026-02-10

Scope: Engineering survey.

Remarks: In area overlapping adjacent zones refer to distortion maps in RMTCRS User Guide to choose system. Working unit is International feet (note: not US survey feet). See NAD83(2011) / RMTCRS Flathead 83 (m) (CRS code 11366) for metric equivalent.

Area of use: United States (USA) - Montana - Flathead.

Coordinate system: Cartesian 2D CS. Axes: easting, northing (X,Y). Orientations: east, north. UoM: ft.

Covered area powered by MapTiler

Center coordinates
-3056165.58 -502406.54

Projected bounds:
-28360384.6 -12122439.46
18639417.42 14116839.17

WGS84 bounds:
167.65 14.92
-63.88 74.71

Puerto Rico - onshore and offshore. United States (USA) onshore and offshore - Alabama; Alaska; Arizona; Arkansas; California; Colorado; Connecticut; Delaware; Florida; Georgia; Idaho; Illinois; Indiana; Iowa; Kansas; Kentucky; Louisiana; Maine; Maryland; Massachusetts; Michigan; Minnesota; Mississippi; Missouri; Montana; Nebraska; Nevada; New Hampshire; New Jersey; New Mexico; New York; North Carolina; North Dakota; Ohio; Oklahoma; Oregon; Pennsylvania; Rhode Island; South Carolina; South Dakota; Tennessee; Texas; Utah; Vermont; Virginia; Washington; West Virginia; Wisconsin; Wyoming. US Virgin Islands - onshore and offshore.

Definition: OGC Well Known Text

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PROJCS["NAD83(2011) / RMTCRS Flathead 83 (ft)",
    GEOGCS["NAD83(2011)",
        DATUM["NAD83_National_Spatial_Reference_System_2011",
            SPHEROID["GRS 1980",6378137,298.257222101],
            TOWGS84[0,0,0,0,0,0,0]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","6318"]],
    PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],
    PARAMETER["latitude_of_center",48.4],
    PARAMETER["longitude_of_center",-114.45],
    PARAMETER["azimuth",320],
    PARAMETER["rectified_grid_angle",-40],
    PARAMETER["scale_factor",1.000142],
    PARAMETER["false_easting",492125.9843],
    PARAMETER["false_northing",492125.9843],
    UNIT["foot",0.3048],
    AXIS["Easting",EAST],
    AXIS["Northing",NORTH],
    AUTHORITY["EPSG","11367"]]

Definition: OGC Well Known Text 2 (2019)

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PROJCRS["NAD83(2011) / RMTCRS Flathead 83 (ft)",
    BASEGEOGCRS["NAD83(2011)",
        DATUM["NAD83 (National Spatial Reference System 2011)",
            ELLIPSOID["GRS 1980",6378137,298.257222101,
                LENGTHUNIT["metre",1]],
            ANCHOREPOCH[2010]],
        PRIMEM["Greenwich",0,
            ANGLEUNIT["degree",0.0174532925199433]],
        ID["EPSG",6318]],
    CONVERSION["Montana Flathead 83 (international foot)",
        METHOD["Hotine Oblique Mercator (variant B)",
            ID["EPSG",9815]],
        PARAMETER["Latitude of projection centre",48.4,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8811]],
        PARAMETER["Longitude of projection centre",-114.45,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8812]],
        PARAMETER["Azimuth at projection centre",320,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8813]],
        PARAMETER["Angle from Rectified to Skew Grid",-40,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8814]],
        PARAMETER["Scale factor at projection centre",1.000142,
            SCALEUNIT["unity",1],
            ID["EPSG",8815]],
        PARAMETER["Easting at projection centre",492125.9843,
            LENGTHUNIT["foot",0.3048],
            ID["EPSG",8816]],
        PARAMETER["Northing at projection centre",492125.9843,
            LENGTHUNIT["foot",0.3048],
            ID["EPSG",8817]]],
    CS[Cartesian,2],
        AXIS["easting (X)",east,
            ORDER[1],
            LENGTHUNIT["foot",0.3048]],
        AXIS["northing (Y)",north,
            ORDER[2],
            LENGTHUNIT["foot",0.3048]],
    USAGE[
        SCOPE["Engineering survey."],
        AREA["United States (USA) - Montana - Flathead."],
        BBOX[47.7,-115.39,49.09,-112.91]],
    ID["EPSG",11367]]

Definition: ESRI Well Known Text

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PROJCS["NAD83_2011_RMTCRS_Flathead_83_ft",
    GEOGCS["GCS_NAD_1983_2011",
        DATUM["D_NAD_1983_2011",
            SPHEROID["GRS_1980",6378137.0,298.257222101]],
        PRIMEM["Greenwich",0.0],
        UNIT["Degree",0.0174532925199433]],
    PROJECTION["Rectified_Skew_Orthomorphic_Center"],
    PARAMETER["False_Easting",492125.9843],
    PARAMETER["False_Northing",492125.9843],
    PARAMETER["Scale_Factor",1.000142],
    PARAMETER["Azimuth",-40.0],
    PARAMETER["Longitude_Of_Center",-114.45],
    PARAMETER["Latitude_Of_Center",48.4],
    PARAMETER["XY_Plane_Rotation",-40.0],
    UNIT["foot",0.3048]]

Definition: PROJ.4

+proj=omerc +lat_0=48.4 +lonc=-114.45 +alpha=320 +gamma=-40 +k=1.000142 +x_0=150000.00001464 +y_0=150000.00001464 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=ft +no_defs +type=crs

Definition: JavaScript (Proj4js)

proj4.defs("EPSG:11367","+proj=omerc +lat_0=48.4 +lonc=-114.45 +alpha=320 +gamma=-40 +k=1.000142 +x_0=150000.00001464 +y_0=150000.00001464 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=ft +no_defs +type=crs");

Definition: JSON

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{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "type": "ProjectedCRS",
    "name": "NAD83(2011) / RMTCRS Flathead 83 (ft)",
    "base_crs": {
        "type": "GeographicCRS",
        "name": "NAD83(2011)",
        "datum": {
            "type": "GeodeticReferenceFrame",
            "name": "NAD83 (National Spatial Reference System 2011)",
            "anchor_epoch": 2010,
            "ellipsoid": {
                "name": "GRS 1980",
                "semi_major_axis": 6378137,
                "inverse_flattening": 298.257222101
            }
        },
        "coordinate_system": {
            "subtype": "ellipsoidal",
            "axis": [
                {
                    "name": "Geodetic latitude",
                    "abbreviation": "Lat",
                    "direction": "north",
                    "unit": "degree"
                },
                {
                    "name": "Geodetic longitude",
                    "abbreviation": "Lon",
                    "direction": "east",
                    "unit": "degree"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 6318
        }
    },
    "conversion": {
        "name": "Montana Flathead 83 (international foot)",
        "method": {
            "name": "Hotine Oblique Mercator (variant B)",
            "id": {
                "authority": "EPSG",
                "code": 9815
            }
        },
        "parameters": [
            {
                "name": "Latitude of projection centre",
                "value": 48.4,
                "unit": "degree",
                "id": {
                    "authority": "EPSG",
                    "code": 8811
                }
            },
            {
                "name": "Longitude of projection centre",
                "value": -114.45,
                "unit": "degree",
                "id": {
                    "authority": "EPSG",
                    "code": 8812
                }
            },
            {
                "name": "Azimuth at projection centre",
                "value": 320,
                "unit": "degree",
                "id": {
                    "authority": "EPSG",
                    "code": 8813
                }
            },
            {
                "name": "Angle from Rectified to Skew Grid",
                "value": -40,
                "unit": "degree",
                "id": {
                    "authority": "EPSG",
                    "code": 8814
                }
            },
            {
                "name": "Scale factor at projection centre",
                "value": 1.000142,
                "unit": "unity",
                "id": {
                    "authority": "EPSG",
                    "code": 8815
                }
            },
            {
                "name": "Easting at projection centre",
                "value": 492125.9843,
                "unit": {
                    "type": "LinearUnit",
                    "name": "foot",
                    "conversion_factor": 0.3048
                },
                "id": {
                    "authority": "EPSG",
                    "code": 8816
                }
            },
            {
                "name": "Northing at projection centre",
                "value": 492125.9843,
                "unit": {
                    "type": "LinearUnit",
                    "name": "foot",
                    "conversion_factor": 0.3048
                },
                "id": {
                    "authority": "EPSG",
                    "code": 8817
                }
            }
        ]
    },
    "coordinate_system": {
        "subtype": "Cartesian",
        "axis": [
            {
                "name": "Easting",
                "abbreviation": "X",
                "direction": "east",
                "unit": {
                    "type": "LinearUnit",
                    "name": "foot",
                    "conversion_factor": 0.3048
                }
            },
            {
                "name": "Northing",
                "abbreviation": "Y",
                "direction": "north",
                "unit": {
                    "type": "LinearUnit",
                    "name": "foot",
                    "conversion_factor": 0.3048
                }
            }
        ]
    },
    "scope": "Engineering survey.",
    "area": "United States (USA) - Montana - Flathead.",
    "bbox": {
        "south_latitude": 47.7,
        "west_longitude": -115.39,
        "north_latitude": 49.09,
        "east_longitude": -112.91
    },
    "id": {
        "authority": "EPSG",
        "code": 11367
    }
}

Definition: GeoServer

11367=PROJCS["NAD83(2011) / RMTCRS Flathead 83 (ft)",GEOGCS["NAD83(2011)",DATUM["NAD83_National_Spatial_Reference_System_2011",SPHEROID["GRS 1980",6378137,298.257222101],TOWGS84[0,0,0,0,0,0,0]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","6318"]],PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],PARAMETER["latitude_of_center",48.4],PARAMETER["longitude_of_center",-114.45],PARAMETER["azimuth",320],PARAMETER["rectified_grid_angle",-40],PARAMETER["scale_factor",1.000142],PARAMETER["false_easting",492125.9843],PARAMETER["false_northing",492125.9843],UNIT["foot",0.3048],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","11367"]]

Definition: MapServer - MAPfile

PROJECTION
	"proj=omerc"
	"lat_0=48.4"
	"lonc=-114.45"
	"alpha=320"
	"gamma=-40"
	"k=1.000142"
	"x_0=150000.00001464"
	"y_0=150000.00001464"
	"ellps=GRS80"
	"towgs84=0,0,0,0,0,0,0"
	"units=ft"
	"no_defs"
	"type=crs"
END

Definition: Mapnik

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=omerc +lat_0=48.4 +lonc=-114.45 +alpha=320 +gamma=-40 +k=1.000142 +x_0=150000.00001464 +y_0=150000.00001464 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=ft +no_defs +type=crs">
	<Layer srs="+proj=omerc +lat_0=48.4 +lonc=-114.45 +alpha=320 +gamma=-40 +k=1.000142 +x_0=150000.00001464 +y_0=150000.00001464 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=ft +no_defs +type=crs">
	</Layer>
</Map>

Definition: SQL (PostGIS)

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 11367, 'EPSG', 11367, '+proj=omerc +lat_0=48.4 +lonc=-114.45 +alpha=320 +gamma=-40 +k=1.000142 +x_0=150000.00001464 +y_0=150000.00001464 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=ft +no_defs +type=crs', 'PROJCS["NAD83(2011) / RMTCRS Flathead 83 (ft)",GEOGCS["NAD83(2011)",DATUM["NAD83_National_Spatial_Reference_System_2011",SPHEROID["GRS 1980",6378137,298.257222101],TOWGS84[0,0,0,0,0,0,0]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","6318"]],PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],PARAMETER["latitude_of_center",48.4],PARAMETER["longitude_of_center",-114.45],PARAMETER["azimuth",320],PARAMETER["rectified_grid_angle",-40],PARAMETER["scale_factor",1.000142],PARAMETER["false_easting",492125.9843],PARAMETER["false_northing",492125.9843],UNIT["foot",0.3048],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","11367"]]');

EPSG:11367