The Thornton unit comprises 2,080 acres located about eight miles northeast of Prosser on the west side of Benton County, and about three miles southwest of the Rattlesnake Slope unit. It was acquired by WDFW in 1996 for mule deer, upland birds, transitory elk (the Rattlesnake Hills herd), sage grouse, and other shrub-steppe obligate species. By 1999 all 1,300 acres of croplands had been converted to native-like grasslands. Thornton supports long ridges of shrub steppe, intermixed with the former wheat fields. Future activities on this site may include the development of small check structures within the drainages to collect spring runoff. This will help maintain available water for wildlife and support more riparian vegetation. Currently, most intermittent water disappears by mid-summer. Snipes Creek bisects the unit and provides limited but important riparian habitat in places. A spring in the center of this unit provides free water nearly year round and other, smaller springs exist in other canyons. The unit is a popular hunting area for deer and elk. Historically, chukar hunting was common but populations have waned in recent years. The unit has two access sites, one along Rothrock Road on the west side and a new one along Case Road on the east side that compensates for the closure of Sharp Road.
Birds of Prey
How to Get Here
Map and Driving Directions
Access Site #1
Driving Directions In Benton Co., and from I-82, take exit 80 at Gap Road. Take Gap Road north 3.5 miles to Hanks Road. Take Hanks east for 4 miles to Rothrock Road. Take Rothrock north for 6.7 miles to a small parking lot on the right.
Parking/Restroom Information Gravel parking lot. No facilities
Other Information No overnight camping or open fires
Access Site #2
Driving Directions Continuing east from the intersection of Rothrock and Hanks Roads, drive 2 more miles to Case Road. Drive north on Case for 4 miles, then 1 mile to the east, then north for 1.5 miles to a small parking area on the left.
Parking/Restroom Information Gravel drive-through parking lot for horse trailers. No facilities.
Other Information No overnight camping or open fires.
Shrub steppe, intermixed with grass CRP fields. Several canyons cross the property, generally from north to south. Good quality shrub steppe with abundant wildflowers in the spring. This area is 3 miles across from Case Road to Rothrock Road.
Sharp Road runs up a major canyon, providing historic access to the center of the property. This road was closed to minimize disturbance in the core habitat, and to reduce illegal dumping and vandalism. Limited disabled hunter drive-in access is available on this site by permit only.
A Discover Pass or WDFW Vehicle Access Pass
is required on all WDFW lands. Learn more at DiscoverPass.wa.gov