In 2005 the National Park Service funded an expedition to characterize the freshwater resources in the northernmost National Parklands in Alaska (Bowden et al., 2005). The primary purpose of this project was to extend the limited base of data and knowledge about the freshwater resources of the Gates of the Arctic Park and Preserve and the Noatak National Preserve. This initiative is part of the National Park Service’s (NPS) Inventory and Monitoring program (Lawler et al., 2009). The 2005 field initiative included landscape and freshwater ecosystem experts from the University of Vermont, the University of Alaska at Fairbanks, the University of Alabama, Utah State University, and the Marine Biological Laboratory. Substantial assistance in preparation and execution of the field work was provided by staff from the NPS Arctic Parks Network (ARCN) in Fairbanks. The study area for the 2005 effort focused on a portion of the Noatak River from 12-Mile Creek to Lake Matcharak in the western region of the Gates of the Arctic Park and Preserve. The team was deployed 13 July, 2005 and operated continuously in the field until taken out on 26 July 2005. Over the course of the two week field period a total of 20 different stream reaches and 11 lakes were assessed. This data release publishes the bathymetric data and digitized polygon lake perimeters for the following lakes: Big Guy Lake, Kipmik Lake, Lake Ermi, Lake Gigi, Lake Pjolene, Matcharak Lake, Omelaktavik Lake, Skeeter Lake, Unknown-1, Unknown-2, Unknown-4,

Key words: Lake, Alaska, Bathymetry, Arctic, Pond, Big Guy Lake, Kipmik Lake, Lake Ermi, Lake Gigi, Lake Pjolene, Matcharak Lake, Omelaktavik Lake, Skeeter Lake, Unknown-1, Unknown-2, Unknown-4

Bathymetric Data Detailed bathymetric surveys were conducted using a GPS-linked, Garmin-153C echosounder attached to an inflatable kayak which was paddled across lakes along specified transect lines. The echosounder recorded water depth as an algorithm of reflections from the bottom of a 70 kHz pulse of sound (0.4 msec in duration) as the GPS unit recorded the corresponding latitude and longitude.

Lake Perimeters Lake perimeters were digitized by eye from imagery in Quantum GIS. The perimeter digitizations were added to the bathymetric data with depth values of zero in order to define the edges of the lakes and extend the bathymetric dataset.

Files This data release consists of the following files:

File Description Bathymetry.csv Bathymetry data. Bathymetry_Metadata.csv Metadata for Bathymetry.csv including column names, descriptions and units of measure. LakePerimeters.geojson Lake perimeters spatial layer, digitized from imagery. Multipolygon. Geographic Coordinate System, WGS 1984. ARCN-Freshwater-Lakes-Bathymetry-Data-Release-Report.html This report. HTML format. 2.7 Mb Columns and Data Types Table 2. Columns descriptions and units of measure. ColumnName DataType Description UnitsOfMeasure Lake character Lake name
Depth numeric Lake name Meters Latitude numeric Latitude Decimal Degrees, Geographic Coordinate System, WGS1984. Longitude numeric Longitude Decimal Degrees, Geographic Coordinate System, WGS1984. BID integer Unique ID
SiteName character Site name