Great Falls’ Elm Crisis

Thousands of Elm Trees were Destroyed by Disease

Kodachrome slide of trees destroyed due to Dutch elm disease in Great Falls, 1989-1990. [1990.034.0001-3]

For Great Falls city boulevards, the elm tree became the most popular choice. Elms were planted rapidly through the American west due to their durability: resistance to cold, drought, and flooding. Elm trees are, however, susceptible to Dutch elm disease. The disease, cased by a fungus spread by elm bark beetles or spread by root to root contact underground, was first reported in Great Falls in 1987.

Injections of Arbotect (essentially an elm vaccine) were used to save some Great Falls elms, however the mixture was so expensive that not every elm could afford to be inoculated. Elms that received a shot of Arbotect were only resistant for three years, and a 16 inch diameter elm cost $199 to be treated, larger trees costing even more. The elm crisis was combatted by the quick removal of elms showing early signs of Dutch elm disease and using a chemical to reduce the spread. Great Falls expected to lose virtually all of its 13,000 elm trees. The ReLeaf Great Falls initiative launched in 1990 to combat the massive loss of trees. The project sought to plant 1,000 new, diverse trees a year from 1990 to 2000.

Image gallery above: Kodachrome slides of trees destroyed due to Dutch elm disease in Great Falls, 1989-1990. “By early 1994, more than 8,000 trees succumbed to the disease,” -Great Falls Tribune, April 19, 1994. Early signs of Dutch elm disease are out-of-season yellowing and withering of leaves on a branch. The disease will then spread to all the branches which will starve the roots and cause the tree to die.

[Images: 1990.034.0001]

Graphic from ReLeaf Great Falls project of recommended city trees published in the Great Falls Tribune April 19, 1994. An important part of the project was to plant a diverse variety of trees to combat the possibility of future species-specific disease that could result in the same mass-death problem for the renewed forest. The ReLeaf project sought donations and made a variety of fundraising efforts to reduce tree replacement costs.

Images above: Selection of details from proof sheets taken by Ray Ozmon of elm tree removal by City Forester Jon Thompson’s team. Photos taken on 12th Street and between 1st and 2nd Avenue North. [1992.062]

City Forester Jon Thompson and team seated on the cut-down elm trees. Photo by Ray Ozmon. [1992.062]

The combination of quick removal of diseased trees, no wild elms in the area, low humidity (fewer beetles), and the ReLeaf initiative aided the Great Falls urban forest's recovery. In 2019, Great Falls was named outstanding urban forestry community of the year from the Montana Urban and Community Forestry Association.

The Electric reported that year: "A study conducted by the U.S. Environmental Protection Agency determined that every urban tree contributes an average of $350 per year to the community in direct environment benefits. These benefits include reduced heating and cooling costs, greatly reduced storm water runoff, less erosion, reduced pollution through carbon sequestering, and others. Based on this report, the city’s public trees provide more than $11.5 million annually in direct environmental benefits." (https://theelectricgf.com/2019/02/11/great-falls-named-outstanding-urban-forestry-community-of-the-year/)

Originally published as a weekly email for October 23, 2020 and published as a blog article July 29, 2022 with more images, information, and number correction to 13,000 tree estimation.