A bridge can be defined as a structure that spans an obstacle or a connecting phase between two periods of time. This EarthCache is an attempt to highlight both!
To log this EarthCache, go ahead and claim it as a find, then e-mail the cache owner with the information below:
1) Is the spot where you are standing part of the upper or the lower Maple River Watershed?
2) How would you describe the affect the dam is having on bank erosion and aggradation in this spot?
3) Take a quick walk to visit the nearby additional waypoint (N43 05.320 W084 24.453) to see the current bridge being used to both span an obstacle and connect two periods of time. Describe how, if at all, bank erosion and the aggradation are different here, further upstream, than at the old bridge/dam site.
4) (Optional): Locate the plaque at the "new" bridge site, provide the name of the gentleman who the bridge was named after in 1966. A pic of you and/or your GPS at this plaque gets you a virtual high-five!
First, the Obstacle:
What is one of the main obstacles bridges often span? Water, of course! From the Island Rd. Historical Bridge Park parking area, wander down the short path to get up close and personal with the Maple River.
How does all that water get to one place? It comes from the Maple River Watershed. A watershed is an area of land, defined by hills and ridges, that drains to a common body of water. According to the Friends of the Maple River (FOMR) organization, the area known today as the Maple River Watershed was created “by the advance and retreat of the southern face of massive ice shields during the ice age."
The Maple River Watershed can be divided in to the Upper and Lower Watershed. The Upper Maple River Watershed covers approximately 513 square miles. It is estimated that more than 50% of the water that flows through the watershed is groundwater, with the remainder from rain and other surface waters.
All that water is bound to draw people near. Rivers are often altered through the use dams for human development, typically for additional water supply and power generation. At this site, by 1845 mill operations began and in 1865 a wood crib dam was built to support the saw/grist mill. In 1912 the dam was replaced with an earth-and-rock dam capped with concrete. Today, the Elsie Dam is the only dam in the watershed that exists on the mainstem of the Maple River. The dam is currently in disrepair and there are ongoing conversations about its' future.
Dams can drastically affect the ecological processes of river environments. Rivers emerging downstream of a dam may be substantially altered from the character of the river entering an impoundment above a dam. Flow patterns reflecting normal, high, and low water conditions over time may be altered, affecting bank erosion. Rate and flow regulation may determine the significance of any bank erosion, with these impacts often becoming less pronounced downstream of the dam.
A dam often traps sediments, critical for maintaining physical processes and habitats downstream. When a river is deprived of its natural sediment load, it can work to recapture it by eroding the downstream river bed and banks. Aggradation, an increase in land elevation, and degradation, a decline, is common in river systems where dams are present due to the depositing of moving sediment. Aggradation occurs in areas in which the supply of sediment is greater than the amount of material than the system is able to transport.
With all that water, this part of the Maple River needed a way to span that obstacle! In 1901 a 160 ft. single-span metal truss bridge was built by Detroit Bridge & Iron Works for only $2,590! The bridge allowed traffic until 1966. No longer passable to either vehicle or foot traffic, but an amazing piece of history. In 2015 the Grist Mill Bridge was placed on the National Register of Historic Places. The bridge deck has the only known surviving example of wood block paving in the state.
Lastly, bridging the TIME:
In 1966 a new and safer $120,000 bridge was opened for travelers to span the Maple River. The bridge was named after a local gentleman who had been a member of the road commission board for 18 years. The Clinton County Newspaper (11/10/66) tells us some about bridge dedication day. It was a cold and windy day in November. With his wife by his side and approximately 75 onlookers, the 4 foot ceremonial scissors failed to cut the blowing ribbon. I imagine there was a chuckle that spread through the crowd as the "smaller, six-inch pair had to be pressed into service". I can almost see the high school band procession as they crossed the new bridge playing the National Anthem. But beyond imagination of a moment most of us will never know, this glimpse into the past has bridged the time between five generations. Uncovering stories about when the world was different, but sometimes not so different at all.
*As with any cache, but especially in the spirit of EarthCaching, please be sure to CITO!
*The information for this cache was obtained via internet search. Primarily a 2010 Upper Maple River Management Plan (unless otherwise noted) by Fishbeck, Thompson, Carr & Huber, Inc.
* Big thanks to the Duplain Township officials for granting permission for this cache!