ASSESSMENT OF PRONGHORN HABITAT POTENTIAL IN EASTERN WASHINGTON BY GEORGE K. TSUKAMOTO JUNE 2006 ASSESSMENT OF PRONGHORN HABITAT POTENTIAL IN EASTERN WASHINGTON GEORGE K. TSUKAMOTO JUNE 2006 This study was financed by the Seattle Sportsmen’s Conservation Foundation and Safari Club International-Central Washington Chapter for the Washington Department of Fish and Wildlife as an initial assessment to determine the feasibility of reintroducing pronghorn antelope into the State. Table of Contents TABLE OF CONTENTS .............................................................................................................. I INTRODUCTION......................................................................................................................... 1 PURPOSE .................................................................................................................................................................... 1 ACKNOWLEDGEMENTS .............................................................................................................................................. 1 HISTORICAL OCCURRENCE ......................................................................................................................................... 1 PREVIOUS INTRODUCTIONS ....................................................................................................................................... 2 STUDY AREA ............................................................................................................................... 4 METHODS .................................................................................................................................... 5 GIS HABITAT SUITABILITY MODEL ........................................................................................................................... 6 Pronghorn habitat suitability model .................................................................................................................... 9 Weights of the variables ....................................................................................................................................... 9 Normalized weighted pronghorn habitat suitability score ................................................................................. 10 Other considerations .......................................................................................................................................... 10 ON-SITE FIELD HABITAT EVALUATION AND SCORING MODEL ............................................................................... 10 Vegetation .......................................................................................................................................................... 11 Terrain slope and aspect (Topographic diversity) ............................................................................................. 11 Water availability ............................................................................................................................................... 12 Size and Continuity ............................................................................................................................................ 12 Landownership/use ............................................................................................................................................ 12 Limitations/obstructions (fences, canals, highways, railroads, etc.) ................................................................. 12 Suitability Score Summary ................................................................................................................................. 12 SITE EVALUATIONS ............................................................................................................... 13 QUILOMENE ............................................................................................................................................................. 13 Location/Landownership.................................................................................................................................... 13 Vegetation .......................................................................................................................................................... 13 Topography ........................................................................................................................................................ 15 Water .................................................................................................................................................................. 15 Size and Continuity ............................................................................................................................................ 16 Climate ............................................................................................................................................................... 17 Limitations ......................................................................................................................................................... 18 Wild Horse Wind Power Project ........................................................................................................................ 20 Habitat Evaluation Score ................................................................................................................................... 21 YAKIMA TRAINING CENTER .................................................................................................................................... 23 Location/Landownership.................................................................................................................................... 23 Vegetation .......................................................................................................................................................... 23 Topography ........................................................................................................................................................ 24 Water .................................................................................................................................................................. 25 Size and Continuity ............................................................................................................................................ 26 Climate ............................................................................................................................................................... 27 Limitations ......................................................................................................................................................... 27 Habitat Evaluation Score ................................................................................................................................... 29 SWANSON LAKES..................................................................................................................................................... 31 Location/Landownership.................................................................................................................................... 31 Vegetation .......................................................................................................................................................... 31 Topography ........................................................................................................................................................ 33 Size and Continuity ............................................................................................................................................ 34 Water .................................................................................................................................................................. 34 Climate ............................................................................................................................................................... 35 Limitations ......................................................................................................................................................... 36 Habitat Evaluation Score ................................................................................................................................... 37 i COW AND ROCK CREEK ........................................................................................................................................... 38 Location/Landownership.................................................................................................................................... 38 Vegetation .......................................................................................................................................................... 38 Topography ........................................................................................................................................................ 40 Size and Continuity ............................................................................................................................................ 42 Water .................................................................................................................................................................. 42 Climate ..............................................................................................................................................................