Greys River Landscape Scale Assessment Bridger-Teton National Forest
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GREYS RIVER LANDSCAPE SCALE ASSESSMENT BRIDGER-TETON NATIONAL FOREST Lincoln County, Wyoming 2004 TABLE OF CONTENTS I. INTRODUCTION------------------------------------------------------------------------------- 6 Overview of the Assessment Process--------------------------------------------------- 6 Overview of the Assessment Area------------------------------------------------------ 7 Overview of Alterations to the Landscape-------------------------------------------- 9 Historic Range of Natural Variability------------------------------------------------ 11 Definition-------------------------------------------------------------------------- 11 Climate History-------------------------------------------------------------------- 11 Hydrologic Cycle------------------------------------------------------------------ 12 Vegetation Patterns---------------------------------------------------------------- 12 Natural Landscape-Scale Disturbances----------------------------------------- 13 Landslides----------------------------------------------------------------- 13 Floods---------------------------------------------------------------------- 15 Local Fire History-------------------------------------------------------- 20 II. EXISTING CONDITIONS------------------------------------------------------------------- 23 Introduction--------------------------------------------------------------------------------- 23 Heritage Resources------------------------------------------------------------------------ 23 Physiography-------------------------------------------------------------------------------- 30 Watershed Function and Aquatic Habitats------------------------------------------- 34 Fluvial Processes and Channel Morphology----------------------------------- 34 Dynamic Quasi-Equilibrium------------------------------------------------------ 35 Bankfull------------------------------------------------------------------------------ 37 Diagnostic Parameters------------------------------------------------------------- 38 Erosion and Sediment Transport------------------------------------------------- 41 Natural Disturbances-------------------------------------------------------------- 41 Human Influences on Hillslopes and Stream Channels----------------------- 44 Existing Condition and Assessment Method----------------------------------- 50 Inland West Watershed Assessment--------------------------------------------- 51 Ecological Status of Riparian and Aquatic Habitats--------------------------- 54 Instream Flow Investigation------------------------------------------------------ 57 Vegetation Communities------------------------------------------------------------------ 58 Forested Vegetation: Background------------------------------------------------ 58 Harvest and Fire History-------------------------------------------------- 59 Harvest Effect on Hydrologic Function--------------------------------- 61 Insects and Disease-------------------------------------------------------- 62 Age-Function--------------------------------------------------------------- 63 Growth Function----------------------------------------------------------- 69 Forest Vegetation---------------------------------------------------------- 69 Stand Structure Classification-------------------------------------------- 71 Properly Functioning Condition ----------------------------------------- 74 Forested Characteristics by Hydrologic Unit Code-------------------- 80 2 Understory Vegetation---------------------------------------------------------------86 Alpine Tundra--------------------------------------------------------------- 86 Mountain Mahogany/Brush------------------------------------------------86 Mountain Shrub--------------------------------------------------------------87 Big Sagebrush----------------------------------------------------------------87 Tall Forbs---------------------------------------------------------------------88 Grassland Meadows---------------------------------------------------------88 Riparian zones/Wetlands-------------------------------------------------- 89 Noxious Weeds and Non-Native Invasive Plants-----------------------89 Grazing-------------------------------------------------------------------------------- 91 Livestock Numbers--------------------------------------------------------- 92 Allotment Status and General Range Conditions----------------------- 92 Vacant Allotments---------------------------------------------------------- 96 Closed Allotments---------------------------------------------------------- 97 Wildlife---------------------------------------------------------------------------------------- 99 Big Game ---------------------------------------------------------------------------- 100 Threatened, Endangered, Sensitive Species-------------------------------------- 103 Ecological and Management Indicator Species---------------------------------- 114 Other Species------------------------------------------------------------------------- 114 Sensitive Plants-----------------------------------------------------------------------115 Transportation System--------------------------------------------------------------------- 115 Overview------------------------------------------------------------------------------ 115 Road Densities----------------------------------------------------------------------- 116 Recreation------------------------------------------------------------------------------------- 116 Assets---------------------------------------------------------------------------------- 116 Trends--------------------------------------------------------------------------------- 117 Areas Not Managed for Recreation------------------------------------------------118 Developed Recreation Facilities----------------------------------------------------119 Visitor Information Services--------------------------------------------------------119 Recreation Opportunity Spectrum------------------------------------------------- 120 Dispersed Recreation Facilities, including Roads------------------------------- 125 Inventoried Roadless Area Management------------------------------------------129 Salt River Range-------------------------------------------------------------129 South Wyoming Range-----------------------------------------------------132 Grayback Ridge--------------------------------------------------------------133 III. DESIRED CONDITIONS----------------------------------------------------------------------136 Heritage----------------------------------------------------------------------------------------136 Watershed ------------------------------------------------------------------------------------ 136 Vegetation------------------------------------------------------------------------------------- 139 Alpine Communities-----------------------------------------------------------------139 Mountain Shrubs--------------------------------------------------------------------- 139 Tall Forbs----------------------------------------------------------------------------- 139 Grasslands, Meadows, Dry Parks-------------------------------------------------- 140 Riparian/Wetlands--------------------------------------------------------------------140 3 Aspen---------------------------------------------------------------------------------- 140 Timber Management---------------------------------------------------------------- 140 Grazing Management----------------------------------------------------------------144 Wildland Fire Management-------------------------------------------------------- 144 Insect and Disease--------------------------------------------------------------------146 Noxious Weeds-----------------------------------------------------------------------146 Wildlife Habitat------------------------------------------------------------------------------ 146 General---------------------------------------------------------------------------------146 Game Species-------------------------------------------------------------------------147 Threatened, Endangered and Sensitive Species----------------------------------147 Management Indicator Species-----------------------------------------------------150 Predator Control----------------------------------------------------------------------150 Sensitive Plants-----------------------------------------------------------------------150 Transportation System--------------------------------------------------------------------- 150 General---------------------------------------------------------------------------------150 Road Management Objectives------------------------------------------------------151 Greys River Road----------------------------------------------------------- 151 Other Roads------------------------------------------------------------------152 Recreation------------------------------------------------------------------------------------- 153 Recreation Opportunity Spectrum------------------------------------------------- 154 Winter Recreation--------------------------------------------------------------------154 Facilities and Recreation Uses----------------------------------------------------- 155 Visitor Information Services------------------------------------------------------- 155 Developed Trailheads----------------------------------------------------------------156 Dispersed Recreation --------------------------------------------------------------- 156 Inventoried Roadless Area Management------------------------------------------156 DFC Change Recommendations---------------------------------------------------