Idaho petroglyphs: a window into the past

Southwest Idaho’s petroglyphs are difficult to decipher, but they’ll probably capture your imagination.

Not much is known about the ancient people who etched drawings into polished brown boulders beside the Snake River in Southwest Idaho. What they left behind, though, is Idaho’s largest collection of petroglyphs in one of its scenic sheer-walled canyons.

There are two clusters of petroglyphs within the Snake River Birds of Prey National Conservation Area, and they’re both really impressive. They’re about three miles away from each other, but entirely separate adventures.

One cluster is at Celebration Park a little upstream of Walter’s Ferry on Highway 41. The other, located at Wee’s Bar on the river, requires a 12-mile round-trip hike or bike from Swan Falls Dam.

Celebration Park petroglyphs near Walter’s Ferry

Archaeologists have dated the petroglyphs in the Snake River Canyon between 100 and 10,000 years old by measuring patination on the rocks. This is the accumulation of manganese, iron and hydroxides, which is also called desert varnish.

Established in 1989, Celebration Park is Idaho’s only archaeological park and is managed by Canyon County. The park includes a historic railroad bridge converted into a foot path that spans the Snake River as well as interpretive information about Idaho’s indigenous, railroad and mining histories.

There are several walking trails, and the trails across Halverson Bar weave among thousands of polished basalt boulders deposited by a 15,000-years-ago deluge called the Bonneville Flood.

The flood occurred when the ancestral Great Salt Lake poured over Red Rock Pass on the Utah-Idaho border, scouring the canyon and depositing the boulders in broad reaches of the canyon where the rushing water lost its carrying capacity.

It’s on these polished, brown-skinned boulders, called melon gravels, that native Americans pecked out petroglyphs somewhere between 100 and 10,000 years ago. They’re on the north side of the river at Celebration Park and on the south side of the river some three miles upstream at Wee’s Bar.

Not much is known about the people who made these works of art. Archaeologists believe native Americans wintered in the canyon where they found warmer temperatures, shelter from the wind and easy access to water and fishing.

Wee’s Bar petroglyphs near Swan Falls Dam

To see the petroglyphs at Wee’s Bar you’ll need to commit to more of an adventure. Lace up some hiking shoes or throw a leg over a mountain bike for a 12-mile round trip through the canyon.

Park your car at Swan Falls Dam, which was the first of dozens of dams built on the Snake River and the first blockade to salmon and steelhead that once returned here every year from the Pacific. Erected in 1901, Swan Falls Dam harnessed hydropower for Silver City mining activities in the Owyhee Mountains.

Archaeologists have dated the petroglyphs in the Snake River Canyon between 100 and 10,000 years old by measuring patination on the rocks, which is the accumulation of manganese, iron and hydroxides.

You can access the dam from sunrise to sunset, but there’s a gate that will prevent passage outside those hours. Plan your trip accordingly.

You start by hiking or riding across the dam, turning left and following a trail that turns into a road after a hairpin turn. Follow this rocky road up about 300 vertical feet and turn right, following another road back down into the canyon going downstream along the river.

The road is somewhat braided, but stay close to the riverbank and continue about 5 more miles. You’ll pass a metal cattle guard and a gate that blocks four-wheeled traffic. A pipe descending the cliff wall on the other side of the river marks your arrival at Wee’s Bar.

There’s a well-worn trail into the field of melon gravel boulders south of the road, and a trail to the riverbank where you’ll find an old stone homestead overgrown with willows.

The petroglyphs are impressive at both locations, but Wee’s Bar provides a three to six hour adventure while Celebration Park is more accessible and includes facilities like toilets, picnic tables and a range for throwing the atl-atl (a native hunting tool that predates the bow and arrow). The Wee’s Bar petroglyphs are in the depth of the canyon, and probably somewhat more photogenic.

Best seasons, weather and time of day to see Idaho’s petroglyphs

If you’re a photographer or simply looking for the most scenic time of day to visit Idaho’s biggest concentration of petroglyphs, you should think about mornings, evenings, spring and fall.

Much of the Snake River Canyon in southwest Idaho has burned in wildfires, and the flora is overrun by invasive species that tend to green up for relatively short periods in the spring. There are spotty wildflowers, not a lot of sagebrush, and a lot of Russian thistle and cheat grass. While this detracts from the character of the area somewhat, resourceful photographers can easily work around the challenge

There’s also no question that the petroglyphs come to life in soft, golden light. They get washed out during mid-day, and most of the petroglyphs are on the south and west-sides of rocks. So aim for spring and late-afternoon light when both the petroglyphs and canyon walls will glow gold, and the greenery that surrounds the melon gravels will be at its showiest.

You can go in summer, but be prepared for harsh sun and heat.

Other activities at Swan Falls Dam and Celebration Park

Swan Falls Dam is the first dam ever built on the Snake River. A tourist attraction in its own right, you must cross it to gain access to the south bank and hike or bike to the Wee’s Bar petroglyphs.

Swan Falls Dam is available for tours from 10 a.m. to 4 p.m. on Saturdays from April through Labor Day. It’s a popular fishing spot, and there’s a boat ramp used for whitewater rafting and motor boat launches.

There’s a non-motorized trail that lead from Celebration Park upstream to Swan Falls Dam on the north side

Guffey Bridge at Celebration Park offers one of a small number of places in the area to cross the Snake River. The one-time railroad bridge, built in 1897, has been restored and offers walking access to trails on the south side of the Snake River.

You may be able to hike upstream to Wee’s Bar from Guffey Bridge, but there’s some private property, and you should go prepared to hike through heavy willows and brush.