September 29, 2020

I spy red!

Color Change: Post-Peak Color

Leaf Drop: Moderate

This is the final Spearfish Canyon Leaf Report of 2020. Spearfish experienced wind and periodic light rain over the weekend. Although the colors are past their peak color change, the slow leaf drop and mild temperatures are allowing us to enjoy the leaves a bit longer.

If you cruise through Spearfish Canyon in the coming days, you will notice a rich ombre of colors – the burnt, dark orange of dry leaves ready to fall along with surprise golden leaves on trees still making their seasonal change. Make sure to look down, as well as up into the heights of Spearfish Canyon for the full color experience – vines of red leaves climbing up low-lying rocks and scattered lime greens along the cliffs.

What causes the leaves to finally drop their leaves? A layer of cells exists where a leaf’s stem connects with a tree’s branch. That layer of cells blocks off the leaf veins that transport water and food. This causes the leaf to dry out and, eventually, fall off the tree. Those leaves bring their remaining nutrients to the ground where they fall, benefiting Spearfish Canyon vegetation and animal residents.

September 24, 2020

Fall foliage at Old Spearfish Dam, South Dakota

Color Change: 90% (High – Post-Peak Color)

Leaf Drop: Low to Moderate

The trees in Spearfish Canyon are at or near peak color change. Take a drive through Spearfish Canyon in the next few days and you will be surrounded by autumn’s vibrant splendor. There are many convenient pull-off areas in the Canyon where you can park your vehicle or bike to get out and take a closer look at the trees and take a selfie or two. #leavesandme

When I drove through the Canyon on Thursday morning (9/24), my favorite areas to see the leaves were the curve past Bridal Veil Falls, Homestake Mining Hydro Plant area near Devil’s Bathtub, and mile markers 18, 20-21, and 24.

Here’s what’s happening in those beautiful fall trees behind the scenes: As the days get shorter and the nights get colder and longer, the leaves are preparing for winter. The leaves stop making chlorophyll, a pigment that absorbs light and provides energy for photosynthesis. Slowly, the green in the leaves starts to fade. The yellows, oranges, and reds of the leaves emerge.

When you are out exploring the Canyon this weekend, you are seeing these chemical processes firsthand. Hope to see you out there leaf peepers!

September 22, 2020

Driving south in Spearfish Canyon near Hydro Plant 2

Color Change: 80% (High)

Leaf Drop: Low to Moderate

It’s the first day of fall, and the autumn colors in Spearfish Canyon are on full display. Perhaps most striking right now are the bursts of golden trees in the higher elevations among the rocks and cliffs. In those areas especially, you can easily witness the change of the seasons from a distance as you cruise through the Canyon byway.

This is the week to experience the multitude of colors in the Canyon: The lime greens of trees just about to transform, and the bright yellow trees leading the way into fall. Some Canyon areas are already at peak color change. Then a Canyon curve later you will see areas hiding their color for a bit longer.

Over the past week the long-distance views in the Canyon have been slightly affected by haze in the air due to the west coast wildfires. How does hazy air affect the leaves in the Canyon? Wildfire smoke may actually increase plant productivity (how plants use energy from the sun for food) according to researchers Kyle Hemes, Joseph Verfaillie, and Dennis Baldocchi. Smoke scatters incoming sunlight, so energy from the Sun can reach even further into dense plant canopies on hazy days.

The warm, sunny days ahead in the forecast are a perfect invitation to continue letting Spearfish Canyon show off her autumnal beauty. Welcome fall!