As of late 2014, more than 95% of the historical USGS topographic maps - almost 179,000 map sheets - have been scanned and published. An estimated additional 4% are in process and are expected to be published in 2015 and 2016.
Asian carp of all types have white, firm, mild flesh, which is excellent table fare, but all Asian carp also have intramuscular bones in the filets that many people find undesirable.
Many studies show that bighead and silver carp substantially change ecosystems where they have been introduced.
At the head of the valley in Yosemite National Park, as if on a pedestal, stands Half Dome, the most colossal and recognizable rock monument in the Sierra Nevada, smoothly rounded on three sides and a sheer vertical face on th
An exponential increase in the population numbers of bighead and silver carp began in the mid-90s and continued through the mid-2000s in parts of the
Both bighead and silver carp become fairly large; records of both species approach 100 pounds, but silver carp over 20 pounds and bighead carp over 30 pounds are uncommon. The North American record for bighead carp is a 106-pound fish from Missouri.
USGS does not currently offer vector downloads in bulk other than by special request only.
Instructions for downloading from The National Map Viewer are located in a Download and Cart user guide. Orthoimagery is downloaded with the following steps:
US Topo maps and the maps of the Historical Topographic Map Collection (HTMC) can be downloaded free of charge, in PDF fo
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