Geocache Description:
Pinniped, from the Latin pinna, meaning wing or fin, and ped, meaning foot, a fin-footed mammal. Pinnipeds are a widely distributed and diverse group of semi-aquatic marine mammals comprised of sea lions, walruses and seals.
Historically, harbor seals hunted salmon in the Columbia River as far upriver as The Dalles and Celilo Falls, 200 miles (320 km) from the sea, as remarked upon by Sir George Simpson in 1841: “… these animals ascend the Columbia in great numbers in quest of the salmon.” (Mackie, Richard Somerset [1997]. Trading Beyond the Mountains: The British Fur Trade on the Pacific 1793-1843. Vancouver: University of British Columbia Press. pp. 191–192.)
In recent years, California and Steller sea lions have entered the Columbia River and fed on white sturgeon, several salmon species and steelhead, some of which are listed under the Endangered Species Act. The sea lions enter the Columbia River primarily in the late winter and spring, swimming as far upstream as Bonneville Dam, 146.1 river miles from the Pacific Ocean.
Sea lions were seen at the dam only occasionally in recent decades until 2001, but in 2002 at least 31 individuals spent late March to mid-May below the dam. That number soared to 109 in 2003; since then, the annual population has fluctuated between 80 and 125 animals, but dramatically rose again in 2010 to 166.
California and Steller sea lions – virtually all males – have arrived at Bonneville as early as September and usually depart in early June. However, the occasional sea lion will try to stay all year. The best sea lion viewing is March to May.
The location near this cache is a good place for viewing sea lions as they chase fish in the white froth below the spillway.
You might also see them as they fish in the tailrace of Powerhouse One.
Managing the sea lion populations just below Bonneville Lock and Dam has been a contentious issue between people trying to protect the sea lions and others hoping to reduce their numbers to help increase salmon runs. The role of the Corps of Engineers is limited to tracking the number of individual pinnipeds and their predation of salmon, steelhead and sturgeon; evaluating the effectiveness of various predation deterrence activities; and keeping sea lions out of the dam’s fish ladders.
Bonneville Lock and Dam is open from 7 a.m. to 5 p.m., every day except Thanksgiving, Christmas, and New Years. There are many other geocaches in the immediate area. Also, the Bradford Island Visitor Center is open from 9 a.m. to 5 p.m. and the Bonneville Fish Hatchery is open from 9 a.m. to dusk. Please feel free to check out these other interesting areas while you are here.
Enjoy a snack or lunch along the way when you search for this cache. There are several picnic area’s at Bonneville Dam.
Please use the parking areas and watch out for muggles when accessing this cache hide it as you found it, there are lots of fishermen that fish in this spot!
This cache has been placed with the approval of the Bonneville Park Manager. Please respect all signage regarding roads and areas not open to the public