The Lake at the End of the World: Tule Lake in Northern California

Tule Lake is situated at the end of the world. It's not that it's so big that the world seems to end beyond its margins, but something more like how it is the place that worlds ended. The lake is located in Northern California near the Oregon Border south of Klamath Falls. It fills a fault graben, a basin that formed when the crust stretched and cracked, with large valleys that sank hundreds or thousands of feet. The Tulelake graben sank enough to disrupt the flow of regional streams, and became a huge, but shallow lake. In this semiarid climate water is precious, especially to birds on the migratory flyway from the arctic to the tropics. It's one of the places where plentiful food allowed millions of birds to rest and fatten themselves to continue their journeys.

But it nearly ended for the birds. Settlers in the late 1800s found that streams could be diverted, and that levees and dikes could be constructed, so that vast portions of the lake dried up and disappeared. The nutrient rich sediments of the lakebed became pastures and rich soils for growing alfalfa or potatoes. In 1928, though, a wildlife refuge was established that preserves the remaining lake area for the birds and other animals. The present lake, as big as it seems in the photo above, is but 10% the area it once was.

The lake was the end of the world for a people as well. The Modoc people lived along the shores of the lake for hundreds, maybe thousands of years, but were forcibly removed in the 1870s. Many elements of their culture were lost as their community was shattered. I wrote more extensively on this sad history in a previous post. The story is compelling...check it out!

This is a dispatch from the road, some short descriptions of our ongoing field class on the geology of California's volcanoes.

Faulting, Volcanism, and Life in Northernmost California: the Tulelake Graben

Gillem's Bluff at Lava Beds National Monument

Lava Beds National Monument at the extreme north end of California is a fascinating place. It preserves hundreds of lava tubes and lava flows only a few thousand years old. It also preserves the memory of a people, the Modoc tribe, who were destroyed so settlers could raise alfalfa and potatoes. And there are lakes that formerly gave life to millions upon millions of birds. The smaller lake that persists (with human help) provides shelter for the migratory birds who remain. The lake basin below Lava Beds is protected as the Tulelake National Wildlife Refuge.

Multiple fault scarps (the shadowed terraces) cross the region north of Lava Beds National Monument

It began with faulting. The crust in this region has been stretched beyond the breaking point, and some of the fault blocks have sunk against the others, forming a series of horsts (the uplifted blocks), and one deep graben (the sunken block). The main fault scarp in the top picture is called Gillem's Bluff. One can just make out the waters of Tulelake at its base.

The faults provided an avenue for basaltic magma to reach the surface. The rough blocky a'a lava in these photographs is the Devil's Homestead flow, which emerged just over 10,000 years ago from fissures at the Fleener Chimneys in Lava Beds National Monument.

The graben became a collecting sump for waters in the Klamath River drainage. The present incarnation of Tulelake covers only about 15 square miles (five miles long and three miles wide), but the lake once extended across one hundred square miles. Diversions of the rivers that fed the lake caused vast portions of the lake to dry up and the new land was converted to agricultural fields. Not that the original European settlers particularly cared, but the lake was a critical stop where migratory birds rested and fed during their long journey between the Arctic regions and their winter homes in central and southern California. The topography literally funneled the birds through to Tulelake and  the Klamath Lakes a bit farther north. The lands here are mostly arid, and the water was a sanctuary.

The birds still come, Sandhill Cranes, Ross's and Snow Geese, Greater White-fronted Geese and many others, more than a million each year, but they face challenging conditions of overcrowding and disease, especially in dry years when there is less water and food (the lake is at the end of the receiving line in terms of water allotments). Avian cholera sometimes kills thousands of them. But they've survived, and I hope they will continue to do so.

Earthly violence in the form of earthquakes and volcanic eruptions created this strange landscape, but water made it productive and full of life. It's a fascinating place to visit, especially in spring and fall when the bird migrations peak.