Having achieved the requisite snow cover and ground temperatures, the state yesterday opened the remaining two regions of the North Slope tundra to all vehicles.
The Department of Natural Resources opened the Eastern Coastal area and the Lower Foothills area as of 4 p.m. Jan. 16.
To open the Eastern Coastal area, the state needed to document six inches of snow and soil temperatures below minus 5 degrees Celsius at a depth of 30 centimeters, while the Lower Foothills required the same soil temperature, but nine inches of snow cover.
Cold weather on the North Slope helped both areas reach the required soil temperatures rather early in the season, but winter storms blew away whatever snowfall had accumulated in the Eastern Coastal and Lower Foothills areas.
That forced several companies pursuing exploration programs on the North Slope to delay seismic surveys in those areas.
Although the Eastern Coastal and Lower Foothills areas now have enough snow cover on average, the department warned of some spots with thin snow cover that should be avoided to protect the tundra.
DNR oversees off-road travel for all state land between the Canning and Colville rivers within around 120 miles of the coast.
The department opened the Upper Foothills area on Jan. 4 and the Western Coastal area on Dec. 28, 2007.
The opening only applies to operators with valid off-road vehicle travel permits, and only applies to state-owned land.
The Bureau of Land Management, which oversees federal land, still has not opened tundra in the National Petroleum Reserve-Alaska to off-road travel.