The coordinates of this Earth cache lead you to a summit on the North riverbank of the Assiniboine river overlooking the confluence of the Assiniboine River and the Souris River. A confluence is defined as the meeting place of two bodies of water. Most people call it a fork or Y.
The Souris river starts in Saskatchewan at the Yellow Grass Marshes north of Weyburn. It is approximately 700 km in length and drains approximately 46,000 square kilometers. It wanders from Weyburn into North Dakota, where it is known as Mouse river, south of Minot and then back north again into Canada through the centers of Melita, Hartney, Souris and Wawaneesa and terminating where it joins the Assiniboine near Treesbank ( close to Wawanesa). The Souris has four main tributaries running into it, namely the Antler River and the Moose Mountain, Gainsborough and Plum creeks. They all contribute to the total flow of the Souris River. The annual flow volume, which is mostly from snow melt and spring rains, varies dramatically from year to year, as does the annual precipitation. The lowest annual flow in recent recorded history was 4.2 million cubic meters in 1937 which compares to the highest of 2.6 billion cubic meters in 1976. The average annual runoff is equivalent to 3 mm of water spread over the entire watershed.
The Assiniboine river starts in Saskatchewan as well, near the community of Preeceville and ends at the confluence with the Red River in Winnipeg. It is approximately 1070 km in length and drains approximately 41,500 square kilometers excluding the Souris River and Qu'Apple watersheds. The Assiniboine river runs through many small towns and villages and the two larger cities of Brandon and Portage la Prairie. The Assiniboine has five tributaries contributing to its total flow, the Whitesand river joining it near Kamsack, Saskatchewan, the Souris, as mentioned above, joining it near Wawaneesa (close to the settlement of Treesbank), Mb, the Birtail River joining it near the Birdtail First Nation, the Little Saskatchewan joining near Brandon, and the Qu'Applelle River joining it near historic Fort Ellice. The annual average flow volume is estimated to be 135.7 million cubic meters. The average annual runoff from the Assiniboine watershed is equivalent to about 9.8 mm of water spread over the entire watershed, roughly 3 times the amount from the Souris watershed. When you visit the confluence personally and watch the rivers flow together, the flow volumes comparisons become evident by sight. But keep in mind, the flow at any given time can be highly influenced by the rainfall or snowfall experienced in either watersheds that the other may not have had.
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This earthcache is located in one of Manitoba'a many Wildlife Management areas.We discovered this beautiful area while in search of another cache. There is a trail leading straight to ground zero that will not be accessible by car during the winter months. Access during those months would be either by snowmobile, cross country skiing or hiking about 1.5 km. We have added a way point N 49 40.790 W 099 34.385 which is the turn off to the trail road.
Logging Requirements. Email the answers to the questions below:
1. As you stand at ground zero, gaze downstream (to the South East)to the first larger summit on the river bank and count the number of larger trees on that summit.
2. Knowing that the elevation of the water on the river is about 337 meters, how high above the river is the cliff you are standing on at ground zero? (If your GPSr does have elevation then estimate the height).
3. Question 3 requires that you measure the speed the Assiniboine river is flowing. To do this, you will need to measure out 2 spots on the river bank 20 meters apart(or whatever distance you are comfortable with). We suggest you mark ground zero with a jacket or camera case and with the GPS still heading to ground zero, walk in the downstream direction parallel to the river along the river bank until your GPSr reads 20 meters (or whatever distance you are comfortable with). Mark that spot with another jacket or something and return to ground zero. Now you are going to time an object floating down the river from the time it passes the ground zero mark until it passes mark you just measured. Don't look for any debris to throw in the river, just find something already floating out there and fix our eyes on it. Pick a bubble or floating log or anything that happens to be floating by. Measure or count the seconds that it takes for the object to float past ground zero to the second mark. Using this elapsed time, you can determine the speed of the river in meters per second. Be careful, don't be oblivious to where you are and walk off the river bank.
4. Post a picture of you and/or your GPS with the confluence of the Assiniboine and Souris Rivers in the background.