Owyhee County -   “Nearly 5 million Acres, some of which has not yet been flown over by eagles”


History and Geology of Owyhee

Historic Ranches: You will ride through these ranches.  Cattle were first brought to the area in the 1860s and thousands of them wintered in this mild climate.

Joyce:  Located on Sinker Creek.  Established in 1865 by Matthew Joyce, still working cattle ranch today.

Colette: Located on Castle Creek, has original Stone House, still a working cattle ranch.

Gabica (Montini):  Located near the confluence with the Snake River with Sinker Creek. The stone barn and bunkhouse are still standing, Oregon Trail immigrant stopover.

*Interesting Note on name of Sinker Creek: In 1847 prospectors were said to have found gold nuggets so large they used them as fishing sinkers!

Cavalry Remount Program - Supplying horses and mules for the US Army was big business for Owyhee ranchers up until WW II. In fact, the Picket Creek Valley in which you are camped was one of the largest of these enterprises.  The Army would supply purebred stallions from as far away as Kentucky, and the ranchers would breed them to the local mustangs and stock horses.


Early People - Native peoples are estimated to have been in this area for 14,000 to 15,000 years.  You will see examples of their culture preserved in Petroglyphys which you will ride by near the Snake River.  Shoshone and Bannock tribes are native to this area and are thought to have acquired horses around the 1700s.

Unusual Owyhee Women

1.) Jane Mason (Owyhee’s Calamity Jane)- was a cattle and horse rustler around 1899.

2.) Joe Monaghan- lived as a man for 30 years without detection.  Worked as a gold miner, cowboy and served on juries at a time when no woman was allowed to!  The undertaker discovered her true sex after she had die in 1904!!

3.) Kittie Wilkins:  The Horse Queen of Idaho   Raised horses from 1885 to 1911.  At one time she had 4000 head (see, you don’t have so many after all!!)  She exported teams by train to the East Coast and sold many to the US Army.


Mining in the area - Gold was discovered on Jordan Creek in 1863.  The resulting gold rush was responsible for many boomtowns and mines and a population much greater than the county has today. Silver City is known as The Queen of Ghost Towns and has many buildings still standing.  The County Seat was first located there but was later moved to a more central location at Murphy.

Many people feel that there is still a lot of gold out there just waiting to be found!

Oreana Valley -The introduction of irrigation to the Upper and Lower Snake River Valleys have made thousands of acres of former desert land into productive farmland.  Alfalfa, sugar beets and potatoes are grown here.  Five cuttings of alfalfa hay are harvested each season.

One interesting note is that the Main Street of Oreana runs true North and South.  Surveyors depend on this Initial Point to establish land boundaries everywhere in Idaho.


Geology of the Snake River Basin


The Snake River plain is one of the most widely known and extensive volcanic regions on Earth. The first eruptions began 15 million years ago in near the southwest corner of Idaho. Since that time, volcanic eruptions seem to have migrated eastward at 1 to 2 inches per year, with the most recent volcanic activity having taken place in eastern Idaho and Yellowstone. Basalt lava flows (dark, more fluid flows from the earth’s mantle) have covered much of the original craters and volcanoes, but time has exposed views into the volcanic past in unusual places. Much of the red rock you will see in the canyons is rhyolite, a more viscous lava flow originating as the continental crust is heated from below. Rhyolite extrusions sometimes erupted violently, resulting in flows of hot ash, which welded over time to form tuff, which you will see as light colored stone, similar in appearance to sandstone.


10 million years ago, a series of large lakes began forming, periodically blanketing southwest Idaho. This series of lakes is referred to as Lake Idaho. Marine fossils are abundant in this region from Lake Idaho’s waxing and waning shorelines.  The lake was permanently drained 1 million years ago when a then-small tributary of the Salmon River eroded head ward, eventually reaching the lake and causing its waters to drain northward, forming the Snake. (This tributary, eroded by the massive flood of water from Lake Idaho, became the Hells Canyon of the Snake River. The rhyolite canyons you will see (Castle Creek, Sinker Creek, Pickett Creek) were also formed as Lake Idaho drained. Windblown lakebed sediment formed many of the bluffs and ‘badlands’ formations that you will see.


‘Murphy Melons’  - 15 thousand years ago Lake Bonneville (Eastern Idaho, Utah) broke through its natural dam, unleashing a monumental torrent, which filled the Snake River canyon. Melon boulders of basalt were ripped from the walls of the Snake River canyon, rounded by bumping against one another and deposited in gigantic ‘gravel’ bars. Some of these can be seen along Hwy 78 outside of Murphy. Petroglyphs were carved on some of the larger rounded basalt boulders along the Snake River thousands of years ago.