Colestin Valley, SOLC property
Friday, May 2, 2025
Weather: mid 70s F and mostly sunny, with occasional cloud cover. No recent rain.
On May 2, 2025 Oregon State University students and wildlife enthusiasts Elliott Bury and Liam Hopkins were joined by Rebekah Bergkoetter of Southern Oregon Land Conservancy, and surveyed the new Colestin Valley Property, located in Bear Gulch and along Chocolate Creek in the Colestin Valley.
Our one-day survey of the Bear Gulch Property was focused on two large basalt outcrops on the property, both of which supported large northern Pacific rattlesnake populations, as well as a large number of western lizards, including some of the largest I have ever seen in Oregon.
The first outcrop was south-southeast oriented, and was situated within an oak woodland, with a small riparian corridor at the bottom of the slope. This outcrop was fairly large and had many complex rock formations, which allows ample habitat for many species. At this outcrop we detected three rattlesnakes, including a large, basking adult that was likely a female. This site was a typical rattlesnake-outcrop found in Jackson County, and likely supports many more species and a large number of rattlesnakes.
Rattlesnake burrowed in a rocky crag
The second outcrop was much more exposed, located along a small creek with dense woodland on the other side. It was dominated by buckbrush and small junipers, and had significantly fewer large, deep holes for potential snake brumation sites. This site was unique, and seemed much more similar to habitat found in the eastern Cascades and Great Basin, rather than the Siskiyou Mountains.
Regardless, this outcrop was quite productive, and supported five rattlesnakes, a southern alligator lizard, a western skink (found a few hundred yards off the property on BLM land), and most notably, a large desert striped whipsnake. This discovery was significant, as this species is only known from five or fewer locales in Jackson County, and this locale is almost certainly the highest elevation this species has been detected in Jackson and Josephine Counties, found at around 3,300 feet. Unfortunately, these snakes are notoriously quick and difficult to photograph, and the individual, about 4-5 feet long, escaped into a deep rock crack before any photos were gathered.
The following species were confirmed on the property:
● Pacific chorus frog
● Southern alligator lizard
● Western skink
● Western fence lizard
● Northern Pacific rattlesnake
● Desert striped whipsnake
The following species are almost certainly present on the property, but were not detected:
● Rough-skinned newt
● Ensatina
● Common sagebrush lizard
● Pacific gopher snake
● Western yellow-bellied racer
● Mountain garter snake
● Ringneck snake
● Northern rubber boa
The following species are potentially on the property, with notes:
● Long-toed salamander - This species is found at high elevations on the east side of Interstate-5 relatively commonly, but the lack of vernal pools may limit them at this site.
● Klamath black salamander - This salamander is associated with outcrops usually also occupied by rattlesnakes, and is likely present on this property, as there are records less than 20 miles away in California. A survey during wetter weather in the winter would likely reveal this species at the first, more sheltered outcrop.
● Western toad - Similarly to the long-toed salamander, the absence of vernal pools may limit this species’ presence on this site.
● Foothills yellow-legged frog - The large waterfall along Chocolate Creek may limit this species’ presence on this site, but the small creeks on the property appear to have great habitat for this heavily water-dependent species.
● Northwestern garter snake - This species is a habitat generalist, and is likely present in the woodland habitat on the property. Cover board surveys may turn up this species as well as northern rubber boa in clearings near wooded areas.
● Sharp-tailed snake - This species is likely present in the oak savannah habitat on the property, but would be virtually impossible to detect without the use of artificial cover objects such as plywood boards. This property is well within their known elevation range, and they could potentially be found in large numbers with cover board surveys.
● California mountain kingsnake - The oak-outcrop we surveyed is ideal for this beautiful-yet-elusive snake. The only limiting factor for this species on this property is the lack of a large water source, but Chocolate Creek and Bear Gulch may be sufficient. This species is known from many locales in Jackson County at similar elevations far from water, so it is likely present at this property. Similarly to the sharp-tailed snake, detection may be difficult without the use of artificial cover.
The Bear Gulch property is an extremely valuable and unique property for herpetofauna, especially snakes, and supports an incredible, unique outcrop system that likely supports a large rattlesnake population. Returning a few weeks earlier in spring while rattlesnakes are still at den sites would reveal the true size of this population, as our survey was likely just after snakes began to leave overwintering dens/brumation sites.
The presence of whipsnakes on this property is significant but not surprising, and helps fill in a gap in their known range between Hilt, California and south of Cave Junction, Oregon.
Ravine at Bear Gulch Preserve
