20240830 07271300 1.0 FALSE Iditarod_National_Historic_Trail_Alignment_Public 0.000 -545227.083700 291270.061200 1132178.517100 1681630.620500 1 Projected GCS_North_American_1983 Linear Unit: Meter (1.000000) Alaska_Albers_Equal_Area_Conic_NAD83 <ProjectedCoordinateSystem xsi:type='typens:ProjectedCoordinateSystem' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xmlns:xs='http://www.w3.org/2001/XMLSchema' xmlns:typens='http://www.esri.com/schemas/ArcGIS/10.8'><WKT>PROJCS["Alaska_Albers_Equal_Area_Conic_NAD83",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Albers"],PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-154.0],PARAMETER["Standard_Parallel_1",55.0],PARAMETER["Standard_Parallel_2",65.0],PARAMETER["Latitude_Of_Origin",50.0],UNIT["Meter",1.0]]</WKT><XOrigin>-13752200</XOrigin><YOrigin>-8948200</YOrigin><XYScale>10000</XYScale><ZOrigin>-100000</ZOrigin><ZScale>10000</ZScale><MOrigin>-100000</MOrigin><MScale>10000</MScale><XYTolerance>0.001</XYTolerance><ZTolerance>0.001</ZTolerance><MTolerance>0.001</MTolerance><HighPrecision>true</HighPrecision></ProjectedCoordinateSystem> 20230629 14423000 20240923 16441200 150000000 5000 BLM-STATE Alaska BLM-THEME Recreation NONE Comprehensive Management Plan Historic Iditarod Trail Iditarod National Historic Trail National Historic Trail National Trail Management Corridor National Trail Right of Way Seward to Nome Trail updated historic Iditarod Trail alignment Version 6.2 (Build 9200) ; Esri ArcGIS 10.8.1.14362 Bureau of Land Management U.S. Department of the Interior, Bureau of Land Management (BLM) Iditarod National Historic Trail 20240830 Alaska Comprehensive Management Plan Historic Iditarod Trail Iditarod National Historic Trail National Historic Trail National Trail Management Corridor National Trail Right of Way Recreation Seward to Nome Trail transportation updated historic Iditarod Trail alignment 1 -165.480805 -147.822787 65.094866 59.817834 20240830 Created in 2023 by the BLM Iditarod National Historic Trail Program, Anchorage Field Office, based on earlier versions of GIS data from multiple sources, including non-BLM. Represents alignment location data for the historic Iditarod Trail between Seward and Nome, and connecting trails as identified in the Resource Inventory and Comprehensive Management Plan (CMP) development and adoption from the 1980s, and subsequent effort by trail and land managers. wnership, and/or management of an individual route segment or site associated with the Trail. Unresolved alignment location issues are known to exist but may not be identified in the Iditarod National Historic Trail data set. Further research may be necessary to validate the historic trail location. <DIV STYLE="text-align:Left;"><DIV><DIV>Under the National Trails System Act, the determination of public access to, and management of individual National Historic Trail (NHT) segments and sites identified as part of a NHT System are the right of individual owners and/or managers of lands, easements, etc. underlying such Trails. Participation in, and delineation of a site or segment as part of the INHT System is up to the individual landowners/manager or holders of easements / valid interests. The data presented herein may not be consistent with data sets for lands or easements owned/managed by other parties, or the federal government for Trail segments and sites located outside of lands managed specifically by the BLM Anchorage Field Office (e.g, ANCSA 17b transportation easements, State RS2477/RST routes). Individual landowners and/or managers, and/or appropriate land records offices, should be contacted for such information.Not for legal use, for display purposes only. Any hard copies or published datasets utilizing these datasets shall clearly indicate a citation. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. User specifically agrees not to misrepresent these datasets.No warranty is made by the Bureau of Land Management as to the accuracy, reliability, or completeness of these data for individual or aggregate use with other data. Original data were compiled from various sources. This information may not meet National Map Accuracy Standards. This product was developed through digital means and may be updated without notification.</DIV></DIV></DIV> Bureau of Land Management, Anchorage Field Office, Iditarod National Historic Trail Program Kevin Keeler Bureau of Land Management Outdoor Recreation Planner Anchorage AK 99507 kkeeler@blm.gov US 4700 BLM Road (907) 267-1207 File Geodatabase Feature Class 0.000 dataset EPSG 6.12(9.3.0.0) 1375 Simple FALSE 1375 TRUE FALSE Iditarod National Historic Trail Feature Class 1375 Iditarod National Historic Trail OBJECTID OBJECTID OID 4 0 0 Internal feature number. Esri Sequential unique whole numbers that are automatically generated. Shape Shape Geometry 0 0 0 Feature geometry. Esri Coordinates defining the features. Land_Owner Land Owner String 100 0 0 Land Owner INHT_Trail_Type INHT Trail Type String 100 0 0 INHT Trail Type INHT_Segment_Name INHT Segment Name String 100 0 0 INHT Segment Name Shape_Length Shape_Length Double 8 0 0 Length of feature in internal units. Esri Positive real numbers that are automatically generated. None 20240923 The Iditarod National Historic Trail (INHT) GIS inventory update was undertaken during the agreed upon contract period between 2022 and 2023 and was conducted for the BLM Alaska State Office by the contractor Logan Simpson (LS) using the following processes. To begin, all existing related Iditarod Trail spatial data was delivered to Logan Simpson. This GIS data was imported as feature classes into a preliminary geodatabase. Additional Iditarod line feature classes were created by the LS team through the heads-up digitization of scanned USGS quadrangle paper maps at a 1:63,000 and 1:250,000 scales. Additionally, the map extents were transformed into a polygon feature class grid attributed with PDF attachments of the original scanned maps. Next, data from the 1986 Comprehensive Management Plan (CMP) on which Public Land Survey System (PLSS) sections the original congressionally designated trail corridor intersects with was extracted and translated to tabular data. This tabular data was geocoded into a polygon feature class of the selected PLSS sections to highlight the CMP intended route of the INHT and was symbolized by the specific section name. Once all the INHT spatial data was compiled, each Iditarod feature class line was characterized and described by BLM INHT Administrator Kevin Keeler. This data was captured and stored below and in each feature classes’ respective metadata. The layers were then organized and subsequently displayed according to their relative accuracy and precision on a GIS map. Next, extensive workshop sessions were held between the LS team and the BLM to meticulously trace the INHT route and judiciously discern the correct and official INHT alignment. The dialogue from these meetings were recorded in the Note feature classes found in Iditarod_Trails.gbd. Areas of uncertainty still existed at the end of this process however and line features were only arbitrarily chosen in such areas. The questionable status of such locations was recorded in the Notes feature classes. At that time, the concept of designating another alignment and creating a separate feature class for an Iditarod Contemporary Trail was brought about. This alignment was developed as well during the aforementioned workshops using data from the Iditarod sled dog race and additional data compiled through other federal, state, and local trail partners. Said data was integrated into the working GIS geodatabase along with the route determination comments which were also captured in the Notes feature classes. Once the alignments for both trails were determined the focus shifted to the development of the feature classes’ attribute table schemas. Critical attributes to the Iditarod Trail’s management were established by the BLM. These attributes were then organized into fields to create a custom feature class fitted for use by the BLM. At this point it was decided additional separate feature classes were necessary to fulfill the requirements of the BLM Ground Transportation Linear Feature (GTLF) and Federal Trail GIS Schema (FTGS) standards. The GTLF feature class was to only include route line features on BLM administered land. The FTGS feature classes were created in the new FederalTrailGISSchema2022.gdb but had identical geometry to main Iditarod_Trails.gdb feature classes. Following the creation of the feature classes attribute tables, the LS team set forth attributing the features to the best of their ability. In order to do this existing line features needed to edited through dissolving, splitting, clipping, and exploding to match the boundaries of the features to which the attribute data was being extracted from. This process created the final feature geometries for the trail lines. Additional data was once again needed for to do this and was gathered by both LS and the BLM. Data was extracted from existing sources such as the CMP and Iditarod Trail feature classes as well as new sources such as historical data from the Alaska Heritage Research Survey (AHRS), RMP and State Area Plan boundaries, and land manger polygons. All data used to attribute the feature classes created by the GIS Inventory Update was stored within the final Iditarod_Trails.gdb. Once all the GIS data was compiled, created, edited, and attributed to its furthest extent it was organized into feature classes divided into appropriate feature datasets within their respective geodatabases. All data used in the GIS inventory was stored within the single Iditarod_Trails geodatabase to fulfill the desires of the BLM to have all its Iditarod GIS data in one location to streamline the management of the National Historic Trail. Once organized, the feature classes and feature datasets created by the LS team were described by written metadata developed in large part by the BLM. Existing data stored within the geodatabases maintained its original metadata. Lastly, as a final product map books of the Iditarod Trail were generated in GIS using the spatial data in the geodatabases. Maps were created at both a 1:63,000 and 1:250,000 scale. An overview index map was also made. The maps represent the INHT and the Iditarod Contemporary Trail and reflect the land manger along with standard political and physical base map features. Guidance for Use of Source Feature Classes: Feature Class Name Reliability/Precision Guidance Notes INHT Primary Trail Oct2017 BLM High/high -This is the best Primary Trail data set. -Use to compare extraction of Connecting Trail layer from INHT ADNR 2011 -Keep as Active Data Iditarod NHT 2011 ADNR High/high -This is the best source of Connecting Trail location data, and is highly reliable as a reference for the Primary Trail. -Use as basis to create a new 2022 Connecting Trail layer -Both Primary Trail & Connecting Trail alignments are accurate and should be used as reference -Keep as Active Data INHT Primary Trail Pre 2014 BLM AKDNR Medium/medium -Use INHT Primary Trail Oct 2017 BLM instead. -Can be used to consider duplicate parallel Primary Trails. -After analysis, to be placed in ‘Archive / Inactive Data’. INHTConnectingTrail2014 BLM Intern edits N/A, but highly valuable data set -Use to confirm location of trails in 2011 ADNR data, and then discard BLM data (making new layer while maintaining this layer). -Ultimately store as Archive/ Active Data (although maybe should be Archive/Inactive Data). NLCS Nat. Scenic and Historic Trails Low/low -Do not use as reference -Data set likely to be replaced altogether by updated and accurate alignment data. -To be designated as Archive/Inactive Data, if even this… INHT pre2014 BLM Low/low -Use as reference only -Can be used to ID segments of connecting trails that may be IDed on BLM Paper Atlas maps and need to be investigated -After analysis, to be placed in ‘Archive / Inactive Data’ INHTConnectingTrail 2018 BLM low/low -Do not use as reference -To be designated as Archive/Inactive Data, if even this… INHT Primary Trail Pre 2015 BLM AKDNR (NHT1 Cong. Desig. Route) High/high -Use INHT Primary Trail Oct 2017 BLM instead. -Place in ‘Archive / Inactive Data’. GTLF BLM Alaska Low/low -Do not use as reference -Data set likely to be replaced altogether by updated and accurate alignment data. -To be designated as Archive/Inactive Data, if even this… USGS Quad N/A -Rename layer as ‘Scanned 1983 BLM Paper Map Atlas 1:63K Last metadata review date: 20240830 Kevin Keeler Bureau of Land Management Outdoor Recreation Planner Anchorage AK 99507 kkeeler@blm.gov US 4700 BLM Road (907) 267-1207 Name: Kevin Keeler Organization: Bureau of Land Management Position: Outdoor Recreation Planner Role: Point of Contact