Glossary of Terms

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1.Creek crossings can be classified as stable or unstable, referring to the substrate of the crossing and/or the area and size of the impact of the crossing. 

    a) Unstable creek crossing - An unstable creek crossing meets one or both of the following criteria: 
    1)  it travels over a soft substrate, 2) it is expanding in length or width.

    b) Stable creek crossing-A stable creek crossing meets one or both of the following criteria: 
    1) it travels over a solid substrate, 2) it maintains a consistent size.

2. Creek crossings can also be classified as 90 degree or low-angle, referring to the angle at  
 which the route crosses the creek. 

     a) 90 degree crossing-In this instance, the route enters straight into the water (at a 90 degree
     angle), travels straight through it and exits the water at a similar bearing. 

    b) Low-angle crossing-The route enters the creek at an angle and remains in the creek as it travels
    across the creek at this angle. In a low-angle crossing, the route remains in the creek for a longer
    amount of time than in a 90 degree crossing.  

3. Great Basin - The dry and mountainous region between the Sierra Nevada and the Rocky Mountains. The term may be used to describe a region of internal drainage (no outlet to the ocean), a biotic region (having similar flora and fauna), or an ethnographic province (based on cultural similarities). 

4. Gullying - A ditch that has been formed by running water and associated erosion.

5. Motorized use - Refers to use by all motorized vehicles, including all-terrain vehicles, motorcycles, and full-size vehicles. 

6. Mechanized use - Refers to use by mountain bicycles; management for non motorized and non-mechanized use prohibits use to all motorized users and to mountain bikers. 
non-motorized use.

7. Non-motorized use - Prohibits use by motorized vehicles and allows use by all non-motorized users, including pedestrians, horse packers, and mountain bikers.

8.Off-highway vehicle (OHV) -  A motorized vehicle designed or adapted for travel over surfaces other than maintained roads; a vehicle intended for operation on unmade surfaces or rough terrain. Can include full-size vehicles (i.e., 4WD vehicles, SUVs),  all-terrain vehicles (ATVs), snow vehicles, motorcycles, etc. Also referred to as off-road vehicles (ORVs). 

9. Rhyolitic craters - Volcanoes composed of a fine-grained light-colored acidic volcanic rock that is similar to granite and usually exhibits flow lines. 

10.Riparian - Refers to something that is related to or located on the banks of a river, stream, meadow, lake or other body of water. Riparian habitat/corridor is the vegetated area along a stream or river. Research shows that riparian ecosystems filter out pollutants from land runoff, prevent erosion, and provide shelter and food for many aquatic animals, making them vital to the health of all other aquatic ecosystems.

11. Rutting - Tracks in the soil formed from the passage of heavy equipment. May lead to erosion, deep depressions in the soil, standing water and artificial drainage channels.  

12. Sagebrush steppe - A dry, largely treeless, level grassland that is mainly dominated by sagebrush, shrubs, and short bunch grasses. Found in the western United States.

13. Sediment loading -The amount of rock material suspended in water (i.e., a river).

14. Spur route - A branch off of a primary route. Is usually a short, one-way route that does not reconnect with the primary route.

15. Stream capture - This refers to a phenomenon that occurs when a route that passes through a 
drainage erodes through the divide between the route and the stream, thereby capturing the stream
and diverting it into the route drainage (i.e., the route and the stream become the same).

16.Tufa - A white, spongy porous type of limestone that forms when underwater springs rich in calcium mix with lake water that is rich in carbonates. Calcium carbonate, or limestone, precipitates out of the water as a solid forming tufa towers that are prevalent in Mono Lake.