Understanding the Land Status Layers

To utilize the Land Mapper to its full potential, it is important to understand the various land status layers, associated attributes, and how the layers were created.

---

The following land status layers are used in the Mapper:

---

Data Sources and Creation of Surface, Subsurface, and Easement Layers

Data Sources

The primary data source for the creation of the land status layers is the Bureau of Land Management's Master Title Plats (MTP). These are the official record of ownership for Federal land and water in the State of Alaska. Each MTP covers a geographic extent of one township (36 square miles). In addition to Federal land and water, the MTPs depict private land, State of Alaska land, areas managed by other Federal agencies, and areas selected by individuals and native corporations for possible acquisition.

The Bureau of Land Management uses official survey plats and notes in the creation of the Master Title Plats. MTPs produced before the mid-1990s were drawn using ink and mylar at a scale of 1:23,760 (i.e., one inch on the MTP represents 23,760 inches on the ground [or 30 chains on the ground - one chain equals 66 feet or 792 inches]). The mylars were then transferred to microfiche cards, and 24" x 18" paper prints were produced from the microfiche cards. From the mid-1990's onward, BLM has produced all MTPs digitally, using Autocad software, also at a scale of 1:23,760. The digital MTPs are then converted to TIF and PDF formats for distribution. An example of a Master Title Plat can be seen here.

In a few isolated cases, USFWS used the distances and directions shown on survey plats to create parcel boundaries.

Many of the hydrographic (river bank, lake shore, coastline) boundaries of parcels shown on the Master Title Plats are based on surveys of the parcels. These surveys were performed at a certain point in time and do not reflect the current on-the-ground position of these ambulatory water features. Because the legal boundaries of such parcels actually conforms to the location of ambulatory water features at any point in time, it is necessary for the parcels in the Surface and Subsurface layers to depict, as closely as possible, the current on-the-ground positions of hydrographic features. To accomplish this, USFWS is using satellite imagery and aerial photographs compiled by the Alaska Statewide Digital Mapping Initiative (see http://www.alaskamapped.org) as the reference for adjusting the original MTP-based hydrographic boundaries of parcels.

Creation of Land Status Layers

The land status layers were digitized from the two primary sources: paper MTPs, and digital MTPs in TIF format. From the late-1980's to the mid-1990's, the Division of Realty used digitizing tables to manually digitize the 24" x 18" paper MTPs. With the availability of digital MTPs in TIF format in the mid-1990's, the Division switched to on-screen digitizing of the MTPs.

Regardless of the source format - paper or TIF file - each MTP was georeferenced to the Public Land Survey System township grid. Parcel boundaries were then traced from the MTP to create the digital land status layers. Attribute information such as serial number, owner type, and status were then entered into the GIS.

While all land features have been digitized, not all hydrographic features have been digitized. Only those water features (lakes 50 acres and larger and rivers three chains wide or wider) within surveyed townships and surrounded by conveyed or selected land have been digitized. You will therefore encounter situations where only a portion of a lake is shown. You will also see areas where a river was not digitized beyond a section or township line. Additionally, there are areas where a hydrographic feature is shown in the surface and subsurface layers, but a corresponding feature is not shown on the Mapper's basemap. This is due to the sources and scales of the various data layers. FWS is currently in the process of adjusting hydrographic boundaries derived from BLM's Master Title Plats to match water features depicted by the Alaska SDMI satellite imagery and aerial photographs (commonly referred to as the Alaskamapped.org Best Data Layer, or simply, BDL).

BLM's Generalized Surface Estate Layer

This layer shows the surface estate land status for the entire state of Alaska. It was compiled by the Alaska office of the federal Bureau of Land Management, using the official land records held by BLM. The status has been generalized, meaning that it doesn't show anything less than one section (one square mile) in size. For example, if a 640 acre section contains a 40 acre private parcel surrounded by 600 acres of Federal land, then only the Federal land is depicted - the 40 acre private parcel is not shown. For this reason, the BLM Generalized layer should be used only as a rough look at the land status, and is suitable for small-scale, statewide mapping. If you are working on a more detailed project or need to know the exact land status of an area, you should consult the BLM Master Title Plats and/or Alaska DNR Status Plats for your area of interest. The exception to this is the land within the National Wildlife Refuges. In this case, the land status shown in the Land Mapper is the same status that is shown on the MTPs.

When viewing the BLM Generalized Surface Estate layer, it is usually best to switch the base map to the Basic Gray base map. This makes it much easier to discern the various land status colors.

---

Maintenance/Update of Land Status Layers

The Division of Realty updates the land status each month, subject to receiving updated MTPs from BLM. For each township which has some type of land status, the date from the MTP is entered into the Sections layer. You can verify the currency of the land status for a township by comparing the MTP date shown in the Sections layer against the MTP date for the most current MTP that is posted on BLM's website. If you find an instance where a township in the Land Mapper is not current, please contact the USFWS Region 7 Division of Realty with the township and range in question. The MTP will then be queued for updating.

Note that the Division of Realty does not track the complete transactional history of parcels within the boundaries of the National Wildlife Refuges in Alaska. The land status layers displayed in this Mapper generally reflect only the first transaction of parcels. For example, when the Bureau of Land Management issues a patent to a native allottee or native corporation, that patent is shown in the land status layers. If the native allottee  or native corporation later sells or otherwise transfers legal ownership of their patented parcel to another party, the land status layers in this Mapper do not reflect that transfer of ownership. The exception to this is when the U.S. Fish & Wildlife Service acquires privately patented land via purchases, land exchanges, or donations. In such cases, the land status layers in the Mapper are updated to reflect the change in ownership from private to Federal.

---

Attribute Schema

The fields and field values for all the layers are documented in the pages following this topic. Refer to these pages for detailed information about the land status attributes for each layer.

---

The Region 7 Land Mapper was developed, and is maintained by, the U.S. Fish & Wildlife Service, Region 7, Division of Realty. Questions, comments,and suggestions should be directed to ak_realty@fws.gov

This page was last updated:  Thursday, March 13, 2025