The Golden Spike Cooperative Wildlife Management Unit (CWMU) lies between the North Promontory Mountains and the Promontory Mountains. This area is part of the basin and range ecoregion. The ranges have elevations of 5400 feet in the north and 5700 feet in the south. The basins are 4900 feet to 5000 feet elevation. The most common elevation is 5200 feet but ranges from 4600 feet to 6300 feet with an elevation difference of 1700 feet. Fifty percent (50%) of the CWMU elevation ranges between 5100 feet and 5600 feet an elevation difference of 500 feet. The Golden Spike Cooperative Wildlife Management Unit (CWMU) is dominated by a cover of Inter-Mountain Basins Big Sagebrush Shrubland (48) interspersed with Agriculture (114). Among Sagebrush Shrubland, there is considerable Great Basin Pinyon-Juniper Woodland (37). Areas of Invasive Annual Grassland (121) and Invasive Perennial Grassland (119) are common. There are also patches of Inter-Mountain Basins Semi-Desert Grassland (76). One of the Golden Spike Cooperative Wildlife Mangement Unit (CWMU) nearest weather stations, THIOKOL PLANT 78 (428668), is about 9.7 km northeast from the northeast edge of the CWMU. THIOKOL PLANT 78 has forty-five (45) years of records, 1962 - 2007. During the FALL (September, October and November) the average precipitation is 3.59 inches, but it can be as high as 8.85 inches or as low as 0.50 inch. During the 91-day FALL period, 18 days will experience greater than or equal to 0.01 inch of precipitation, 9 days of greater than or equal to 0.10 inch, or 2 days of the greater than or equal to 0.50 inch of precipitation. Snowfall during the FALL averages 2.8 inches but can be as high as 18.8 inches. FALL temperature at THIOKOL PLANT 78 averages 48.0 degrees F. but can be as high as 98.0 degrees F. or as low as -17.0 degrees F. During the FALL, 47 days will be below freezing (32 degrees F.) and 3 days above 90 degrees F.