Alaska’s forests felt the impact of gold mining. In contrast to the rainy coast-al region familiar to Muir, the interior featured warm and dry summers. Largely because of the Gold Rush, forest fires burned continually. Miners used fire to clear woods and thaw permafrost for prospecting, and wood fueled steamships on the Yukon and other rivers.48 Miners deliberately set forest fires to scorch and dry out trees to make them more useful as fuel. In the course of a winter a pair of miners might consume 30 to 60 cords of wood. Average-sized steamboats needed 30 cords daily, large ones 50 cords. Between St. Michael on the lower Yukon and Dawson across the Canadian border, a paddle wheeler used 150 to 1,000 cords. At the height of activity after the turn of the century, about 250 steamers plied the Yukon.49
In addition to mining operations, white settlers employed fire for camp-ing, signalcamp-ing, protection from insects, and killing green trees to provide fire-wood and clear land for agriculture. An 1899 view of the Yukon River above Circle City: “Smoke on all sides fills the air, as camp-fires are built and not extinguished, and the flames slowly climb the mountainside, destroying the much-needed wood, and spoiling the picture otherwise so beautiful.”50 Whites copied some practices from Alaska Natives, who used fire for many purposes, from signaling and driving game to entertainment. Both Natives and whites exercised little care to maintain control of their fires. Escaping or deliberately freed fires had rendered interior Alaska in part an unnatural environment prior to Euro-American contact.51
Lightning caused fires in the interior and, before the end of the 19th Cen-tury, Indians probably set most of the fires. The Gold Rush accelerated burning.
Geologist Alfred H. Brooks observed in 1911 that
hundreds of square miles of timber have been burned off the Yukon Basin during the last decade. This burning of timber is in part done purposely by both whites and natives in order to get rid of insect pests or to improve the growth of grass near their habitations, and is in part due to carelessness. . . . [T]he amount of timber destroyed by the natives is small compared with that for which the whites are responsible. Many a white man has deliber-ately started a forest fire which has swept over miles of country solely that he might obtain a few acres of dry wood for winter use. If this willful waste does not stop, the time is not too far distant when there will be a scarcity of timber even for local use.
Settlers commonly believed that fire improved the country by increasing grass and moose browse, killing insects, and easing prospecting. They could see scant use for spruce forests except as fuel and construction material.52
An unknown but vast acreage burned between 1898 and 1939, when the Alaska Fire Control Service originated. A fire that started along the Valdez-Eagle trail at Mosquito Fork Flat in 1922 burned a swath 48 miles long by 30 miles wide. Construction workers started fires that consumed more than 100,000 acres at Chatanika River in 1926 and 128,000 acres at Copper River in 1927. A trapper, probably by accident, is believed to have set the Sheenjek River fire that blackened 312,320 acres in 1937. After the Fire Control Service became effective in 1942, aided by reduced activity in the forests, burned acre-age dropped precipitously except in dry years (Table 4.1).53
Wood consumption rose in the interior as population grew and mining op-erations became more mechanized. Sawmills cut spruce in the river valleys for
tabLe 4.1. Forest Acreage Burned in Alaska, 1940–1970
Year Acres Burned Year Acres Burned Year Acres Burned
1940 4,500,000 1951 221,669 1962 38,975
1946 1,438,963 1957 5,049,661 1968 1,013,301
1947 1,431,665 1958 317,215 1969 4,231,820
1948 35,190 1959 596,574 1970 113,486
1949 18,147 1960 87,180
1950 2,063,983 1961 5,100
Source: (1940–1954): Harold J. Lutz, Ecological Effects of Forest Fires in the Interior of Alaska. USDA Tech. Bull.
No. 1133. Washington, DC: March 1956, 14; (1955–1970): U.S. Dept. of the Interior, Bureau of Land Manage-ment, Alaska Fire Service, 1992 Fire Statistics. Fairbanks: 1993, 21.
Note: Nearly all acreage is in interior Alaska. Low and high figures reflect reduced activity in war years and climate variations.
lumber and to support World War II construction. Mining operations, especial-ly dredges, continued to consume great quantities of firewood. One gold dredge used up 1,500 cords annually between 1913 and 1947.54 Steamboats, homes, placer mines, railroads, and other businesses required large volumes. Until mid-century, Fairbanks heated itself primarily by burning wood, directly or in a steam-producing plant.55 Settled in 1901, the town had to send woodcutters 33 miles to the Salcha River for its supply in 1909. By 1916 the town needed 100,000 cords annually, enough to create a pile 4 feet high and deep, 152 miles long. Mining consumed more than 70 percent of the wood, and heating and power generation about 12 percent each.56 For great distances around popu-lated or industrial sites, hills stood shorn of trees. When introduction of coal and fuel oil reduced woodcutting, the forests recovered some of their natural character by statehood, nearly a half-century after Muir’s death.57
In the Southeast, Russians operated sawmills to build ships and other facili-ties, primarily near their capital, Sitka. Canneries, fish traps, housing, and rail-road construction required larger amounts of wood in the American period, as did heating. World Wars I and II called for wood from the Southeast to be used in aircraft and military facilities. Attempts to launch a pulp industry failed be-tween 1913 and the mid-1920s58 but succeeded in 1954 at Ketchikan and 1959 at Sitka.59 International demand for pulp and, to a lesser extent, lumber from the Southeast rapidly increased at the time of statehood. Massive clearcutting wrought such violence on old-growth forests and wildlife that environmental-ists (including, prominently, John Muir’s Sierra Club) and wildlife managers or-ganized to oppose it, setting in motion a struggle that lasted out the century.60
Interior forests, while frequently ravaged by fire, did not lend themselves to large-scale cutting for lumber and pulpwood after statehood. Relatively small in diameter and found along scattered river valleys seldom reached by roads, they cost too much to harvest. Only a small market for the wood existed locally, and that need could be met by lumber from Canada or the Pacific Northwest, de-livered by the Alaska Railroad.61 Although fires continued to burn considerable acreage after statehood, the interior suffered only slight habitat degradation and fragmentation from logging roads.
Loss of trees degraded stream valleys, and broader environmental changes followed forest fires. White spruce, the dominant upland tree, burned readily.
Aspen and paper birch usually replaced it, and a full return to the white spruce climax stage required about 160 years. Fire tended to kill small furbearers, es-pecially martens, weasels, foxes, and lynx. In that respect it worked a dispro-portionate hardship on Indians, who relied on trapping for income. Birch and aspen growth favored moose, at least until the trees grew taller. Loss of white spruce and the lichens growing on them and on the forest floor had a direct det-rimental effect on caribou. Recovery of lichens took 40 years or more. The Gold
Rush, perhaps supplemented by climatic warming, almost certainly reduced caribou populations in subarctic Alaska. Burning added nutrients to the soil but depleted the supply of timber needed for economic development.62
Neither Muir nor others of his time could foresee the effects of global warming to be manifested in the 21st Century. Alaska’s average temperature rose about 4 degrees F from 1960 to 2000 and promised to continue. A warmer climate favored the spread of bark beetles and fire, reducing the white spruce forests of the interior and associated populations of caribou and marten. Melt-ing permafrost would cause large-scale land erosion, siltation of watercourses, and further loss of spruce forests. Tundra would be progressively converted to steppe. Release of carbon by fire and permafrost melting would increase atmo-spheric carbon dioxide, accelerating the changes. Rising sea levels would de-stroy coastal habitat for great numbers of waterfowl and other creatures. Higher ocean temperatures would diminish populations of salmon and affect sea mam-mals. In the Arctic, sea ice melting would jeopardize the survival of seals and Wood yard at Tanana River Railway, ca. 1905–1910. Cole coll. 76-38-20, University of Alaska Fairbanks, Alaska and Polar Regions Archives. The railroad burned wood in its lo-comotives, used it for railroad ties, and delivered it to mining sites. Added to forest fires, the use of wood for mining, steamboats, railroads, heating, and power generation stripped many hills and valleys of trees.
polar bears. Many or most of the glaciers so loved by Muir could disappear.63 The ecological impact of global warming might well exceed all the depredations of pre-statehood eras.