Lake Iliamna

Iliamna Lake Nanvarpak, Nila Vena
from the northern shore
Location	Lake and Peninsula Borough, Alaska
Coordinates	59°32′12″N 155°01′28″W / 59.53667°N 155.02444°W / 59.53667; -155.02444Coordinates: 59°32′12″N 155°01′28″W / 59.53667°N 155.02444°W / 59.53667; -155.02444
Lake type	oligotrophic
Primary inflows	Newhalen River, Illiamna River, Pile River, Copper River
Primary outflows	Kvichak River
Basin countries	United States
Max. length	77 mi (124 km)
Max. width	22 mi (35 km)
Surface area	1,012.5 sq mi (2,622 km2)
Average depth	144 ft (44 m)
Max. depth	988 ft (301 m)
Water volume	27.7 cu mi (115 km3)
Residence time	7.8 years
Surface elevation	46 ft (14 m)
Settlements	Iliamna, Newhalen, Kokhanok, Pedro Bay, Igiugig
References

Iliamna Lake or Lake Iliamna (Yup'ik: Nanvarpak; Dena'ina Athabascan: Nila Vena) is a lake in southwest Alaska, at the north end of the Alaska Peninsula, between Kvichak Bay and Cook Inlet, about 100 miles (160 km) west of Seldovia, Alaska.

It is the largest lake in Alaska, third largest lake entirely in the United States, and twenty-fourth in North America. (While all five Great Lakes are considerably larger, only Lake Michigan lies completely within US territory.) Covering about 2,600 km² (1,000 sq. miles), Iliamna Lake is 77 miles (124 km) long and up to 22 miles (35 km) wide, with a maximum depth of 988 feet (301 m). Through the Kvichak River, its waters drain into Bristol Bay.

The lake is marked as 'Oz[ero] Bol[shoy] Ilyamna' (Big Ilyamna Lake) on the Russian Hydrographical Department's Chart 1455, published in 1852. On an earlier Russian map, from 1802, the lake was named 'Oz[ero] Shelekhovo' (Lake Shelekov) after Russian explorer Grigory Shelekhov. According to G.C. Martin, of the United States Geological Survey, Iliamna is said to be "the name of a mythical great blackfish supposed to inhabit this lake, which bites holes in the bidarkas of bad natives."

The name Iliamna is derived from the Inland Dena'ina Athabascan name Nila Vena, which means island's lake.

Originally constructed by the Alaska Road Commission during the mid 1930s, the Williamsport-Pile Bay Road is a utility-class road maintained by the Alaska Department of Transportation & Public Facilities. Connecting Pile Bay on the lake's northeast side with Williamsport, a tiny settlement on the Iliamna Bay of Cook Inlet (about 100 miles (160 km) southwest of Homer), the road is 15.5 miles (24.9 km) long and one lane wide with four bridges. The Williamsport-Pile Bay Road is maintained as a gravel utility road for the purpose of hauling boats and freight, and is not intended for general purpose use. The road allows boats small enough to be hauled across the road's bridges an opportunity to portage from Cook Inlet to Bristol Bay, saving a trip on the open ocean which involves traveling around the Alaska Peninsula. For this and other reasons, the road is also believed to significantly reduce fuel costs for the Lake Iliamna and Bristol Bay regions.