Kepros Mountain Hike - Boise National Forest

A spacious ridge ramble in the Danskin Mountains with abundant wildflowers and views of snow-covered Trinity Mountains and Arrowrock Reservoir

Trip Stats

• Overview:  Take a solitary and refreshing walk along a lush and undisturbed landscape close to Boise with views of Shafer Butte, Trinity Mountains and Lucky Peak Lake.  Trail begins at Blacks Creek Road summit on a steep single-track motorcycle trail with some steep ascents and descents, then meets with a jeep trail that ends at the summit of Kepros Mountain.
• Distance:  9.7 miles out and back (4.85 miles to Kepros Mountain).
• Elevation:  Trailhead 4,780 feet, Kepros 5,422 feet.  Net gain to summit is 1,540 feet; net loss to summit is 930 feet.
• Map:  USGS topo - Arrowrock Dam, ID 7.5 min.
• Coordinates Kepros Mountain:  43.33.33'36.06"N, -115.56'21.71"W
• Difficulty:  Moderate effort; trail is not marked but path easy to find.  Compass and topo map helpful.  Some short steep climbs on return from summit.
• Directions to trailhead:  Drive I-84 east of Boise and exit Blacks Creek Road (Exit 64). Take a left (north) onto Blacks Creek Road and travel 6.4 miles to intersection with signs for Prairie, Idaho.  Take a left at this intersection driving toward Prairie. Shortly, the road becomes gravel. From this intersection, travel another 4.6 miles to the summit of Blacks Creek Road and park in large lot to the right of road (you will pass a parking lot to the right 0.6 miles before this second large parking lot).  This is a popular ATV trailhead with the ATV road heading to the right (east).  Cross Blacks  Creek Road (west) to get on Kepros Mountain trailhead.

              Total distance from beginning of exit ramp off I-84 to trailhead parking = 11.1 miles

• Geology:  Granite from Atlanta Lobe of Idaho Batholith - Cretaceous age (85 - 67 Ma).

Kepros Mountain Hiking Route and Elevation Profile
Trailhead (green circle) begins at summit of Blacks Creek Road from large parking lot.  It initially climbs a steep motorcycle track whose tread can be seen on 3 short hills from parking lot.  Trailhead at 4,780 feet, summit at 5,422 feet

Trailhead for Kepros Mountain looking west - motorcycle trail can be seen on 3 short and steep hills
Blacks Creek Road in foreground

"Even though age diminishes our physical capacities, it will happen even faster if we don't test ourselves."
- Mike Carlson, Five-time Race to Robie Creek Champion

​Three down and one to go after summiting Kepros Mountain - that is, Fred and I have completed three of the "Grand Slam Peaks" that Tom Lopez describes in his website, Idaho:  A Climbing Guide.  Lucky Peak, one of the Grand Slam Peaks is our frequent training hike.  Cervidae Peak is another that I posted on my website.  Kepros is the third.  Mount Heinen is the fourth and final peak of the "Grand Slam" we will  summit in the next few weeks.

Initial single track trail
Top of Shafer Butte north of Boise on distant horizon

The ecology in these foothills near Blacks Creek Road may be described as "reference" - an area with mostly native plants that shows us what this land looked like in the past; an area that has not been disturbed.  I didn't see many invasive plants and 2 species of astragalus were healthy.  It was a delight to walk on a trail near Boise devoid of cheatgrass, in a landscape full of sagebrush and native grasses.

The easiest way to find this unmarked trailhead is to drive Blacks Creek Road 11 miles north from the exit ramp off I-84 until it reaches a summit and begins to descend.  We parked at the large lot on the east side of the road along with some trailers and people getting their ATV's ready to ride trails to the east.  The trail to Kepros Mountain begins on a single track going straight up 3 short steep hills to the west off Blacks Creek Road. 

​From beginning to end, this hike in late April is a wonderland of green and vivid hues of purple and yellow dotted throughout.  Hiking through these sagebrush hills gave me a light feeling of air and space and a renewed appreciation for the landscapes of southern Idaho.

Larkspur and Arrowleaf Balsamroot

The initial single-track trail winds through a sea of sagebrush over rolling hills and past rusted metal signs and occasional core stones of granite.  There are some bypasses around the highest elevations:  we took a good one that met up with the ridge jeep trail to avoid more climbing​, about 2 miles into the hike on the east (right) of the ridge.  The bypass was not at this time marked with a cairn, however, the path it took was clear.  At this point we saw our first view of Lucky Peak Lake and Boise to the west.  Along most of the hike the snow-capped Trinity Mountains loom on the east horizon.  As we climbed, vegetation became even more thick and green.  The trail intersects a creek near the summit with pines lining its sloping banks that was tempting to explore.

Astragalus purshii

Single track trail meets with jeep trail ~ 2 miles into hike; it stays level, then winds up and down to Kepros Mountain left-center horizon

Arrowleaf Balsamroot
Balsamorhiza sagittata

Idaho Batholith granite - Trinity Mountains on horizon

Arrowrock Reservoir from summit of Kepros Mountain

Pretty sure this is a gopher snake - looks like a rattler but this one had no rattle

From Kepros Mountain summit looking northeast to Arrowrock Reservoir

George Kepros, according to Idaho:  A Climbing Guide website,  homesteaded in this area and this is how the Mountain got its name.  I looked into the history of this land and found a George N. Kepros, who is buried in Boise died at age 92 in 1973.  He may be the man that Kepros Mountain is named after.

The final push to the summit is steep.  Fred and I hit this summit on the perfect day - high clouds, expansive 360 degree views that we were unaccustomed to seeing, as we hadn't been in this "neck of the woods" before.  This perspective of Lucky Peak, a summit we have been on many times, is unique because the north side is so forested - this is not seen from Boise looking at its south slopes.

After signing the summit register and enjoying a peaceful break, we hiked the nearly 5-mile trek back to our truck.  As Fred led the way back, I kept falling behind because there were so many things to photograph.  There's some climbing to do on the way back.  We took the same bypass on the east side of the trail that we took earlier to the single track.  So peaceful is this hike, and late April/early May probably the best time to do it.  Fall hunting season probably not a good time.

So far Kepros is our favorite of the four Grand Slam Peaks - but we haven't hiked Mount Heinen yet.  We will let you know what we think after we summit Heinen, the  last of the Grand Slam Peaks!

Summit register

Kepros Mountain summit looking west - Lucky Peak mid-horizon

Mertensia (Mountain Bluebells) on top of Kepros Mountain