Thank you for your question regarding your red maple. Unfortunately, in the absence of pictures it is very difficult to provide you with an assessment for which I would have much confidence. For this reason, I am very hesitant to make suggestions for actions that you should take at this point (late March 2026).

However, based upon the information that you provided in your question I would suggest at this point that you NOT rush to conclusions. It would be premature to dig up and replace the tree. The fact that only one side (east side) seemed affected in 2025 is important. When this is seen on red maples in Minnesota, and probably also true for South Dakota, this usually points to environmental stress rather than a simple leaf disease. A condition known as leaf scorch can develop in red maples during times of high summer temperatures. I suspect that during summer 2025 your tree may have experienced this. Your red maple should soon start leafing out. Keep an eye on the east side of the tree. If there is normal foliage appearing, this would be consistent with environmental stress having occurred in 2025. See the following for further information regarding maple leaf scorch, and for suggestions of what you might do in 2026 to prevent a recurrence of this condition:

https://apps.extension.umn.edu/garden/diagnose/plant/deciduous/maple/leavesedges.html

https://pnwhandbooks.org/plantdisease/host-disease/maple-acer-spp-leaf-scorch

https://hortsense.cahnrs.wsu.edu/fact-sheet/maple-leaf-scorch/

Another possibility, though less likely than environmental stress, is that in 2025 the tree was showing early signs of a fungal disease known as Verticillium wilt. This is caused by a soil fungus known as Verticillium dahlia. There is no effective treatment for this disease. If present, often only one side of the tree is affected. See the following:

https://www.extension.iastate.edu/news/2005/jun/071602.htm

https://www.canr.msu.edu/news/verticillium_wilt_refresher

https://hort.extension.wisc.edu/articles/verticillium-wilt-of-trees-and-shrubs/

My suggestions are:

1). Do nothing yet at this point. Wait until June and see how the tree looks. If there is blackening of the leaves or any other abnormalities, take some pictures and send to us. We would be glad then to revisit your situation.

2). Do not apply fungicide. Without a good diagnosis of what is affecting the maple, there would be no reason to go down this route.

3). If you see any dead branches these could be pruned out. You could do this, or you could hire a professional licensed arborist. Avoid, however, pruning any live branches. See:

https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional

Good luck. Please keep in touch with respect to how things look in another few months.