| Step 1. |
A. Tributary site. Go to Step 6.
B. Mainstem Site. Go to Step 2. |
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| Step 2. |
A. River channel mostly natural. Go to Step 3.
B. River artificially channelized. Channelized Mainstem. Channelized mainstem sites are highly modified areas where the river course has been straighten out and solidified by concrete or other heavy structure. These sites are most commonly located in urban areas but may also occur in agricultural areas where the river has been modified for irrigation or flood control. Gradient of the river is usually low (<0.5 percent). |
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| Step 3. |
A. River contained by canyon. Go to Step 4.
B. River contained by valley. Go to Step 5. |
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| Step 4. |
A. Substrate large boulders or bedrock, gradient high. High gradient Canyon Mainstem. This could include area were the Bear River has cut canyons through lava flows (basalt) such as the Black Canyon in Idaho or other resistant rock layers. The gradient in these areas is usually relatively high (2 - 8 %) and the substrate large. The flow in canyon reaches is often controlled by dams.
B. Substrate a mixture of boulders, cobble, and sand, gradient moderate. Moderate Gradient Canyon Mainstem. This might represent areas where the Bear River cuts through resistant layers within mountain ranges, like the Oneida Narrows reach in Idaho. Gradient is usually moderate (1 - 2%). |
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| Step 5. |
A. Substrate mixture of cobble, gravel, sand and silt, with cobble and gravel prominent, gradient low to moderate (0.5 - 1%). Moderate Gradient Valley Mainstem. These areas are usually located below canyon reaches or large tributaries where larger substrates are being deposited. This type of reach is also more common higher in the Bear River Drainage.
B. Substrate mostly silt and sand, with isolated areas of cobble or gravel, gradient is low (<0.5%). Low Gradient Valley Mainstem. This is probably the most common Bear River Mainstem reach type in the drainage. The river often meanders through agricultural areas in this type of reach. |
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| Step 6. |
A. Stream channel mostly natural. Go to Step 7.
B. Stream artificially channelized. Channelized Tributary. Channelized tributary sites are highly modified areas where the stream course has been straighten out and solidified by concrete or other heavy structure. These sites are most commonly located in urban areas but may also occur in agricultural areas where the stream has been modified for irrigation or flood control Gradient of the stream is usually low to moderate (<0.5 - 2%). |
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| Step 7. |
A. Stream in valley. Go to Step 9.
B. Stream in mountain canyons. Go to Step 8. |
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| Step 8. |
A. Gradient high (>5%), substrate mostly cobbles, boulders, and bedrock which small patches of sand and silt. Mountainous High Gradient Tributary. This type of reach is most common in headwaters or where stream is cutting through resistant geologic layers.
B. Gradient moderate (1-5%), substrate mostly gravel, cobble and boulder, with patches of sand and gravel. Mountainous Moderate Gradient Tributary. This type of reach is common in the Bear River Drainage.
C. Gradient low (<1%). Substrate predominantly silt, sands and gravel, with patches of cobble. Mountainous Low Gradient Tributary. This type of reach is usually found in areas where something controls the drop of the stream like a dams (including beaver dams), large deposits of sediment from a tributary, rock slide or avalanche. |
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| Step 9. |
A. Gradient moderate (1-3%), substrate mostly gravel, cobble and boulder, with patches of sand and silt. Valley Moderate Gradient Tributary. This type of stream reach is common from the mouths of canyons extending well into the valley.
B. Gradient low (<1%), substrate mostly silt, sand and gravel, with patches of cobble. Valley Low Gradient Tributary. This type of reach is most prevalent near where streams flow into the mainstem Bear River in valley locations. |
