Thunder Mountain Trail, Red Canyon, UT


Runtrails' Web Journal
Previous       2016 Journal Topics       Home       Next



"On Kofa National Wildlife Refuge, the Castle Dome and Kofa Mountains rise abruptly   
from the plains of the Sonoran Desert. The two mountain ranges dominate the
665,400-acre refuge, of which more than 80% is designated as wilderness. Although
these mountains are not especially high (the tallest peak is less than 5,000 feet),
they are extremely rugged and provide excellent habitat for plant and
animal species adapted to the harsh desert climate."
 ~ U.S. Fish & Wildlife Service website re: Kofa National Wildlife Refuge

The highest peak in the wildlife refuge is Signal Mountain at 4,877 feet. It is in the Kofa Mountain Range. It is more difficult to spot from a distance than shorter Castle Dome, however, because of the dome's unique shape.

During the five months we hung out at the Yuma Proving Ground's Desert Breeze RV Park this winter, we could see the iconic Castle Dome butte in the distance from almost everywhere we hiked and rode our bikes -- the hills behind our campground, the nearby Laguna Wildlife Conservation Area, Mittry Lake, Imperial Dam Long-Term Visitor Area and surrounding BLM lands, the overlook on Ferguson Road, Imperial National Wildlife Refuge . . . and every time we drove north on US 95 from Yuma.

View of the Castle Dome Mountains in the distance from BLM lands adjacent to Imperial Dam LTVA

This largest of the domes in the Castle Dome Mountains, and its namesake, is "only" about 3,788 feet elevation -- with a prominence above the desert floor of less than that at only 2,088 feet -- but it is the highest peak in its mountain range and so unique that it is an easy landmark to spot.

In fact, I sometimes used Castle Dome and/or its smaller domed little brother when hiking somewhere new as one way to keep my bearings. The big and little domes were almost always to my northeast.

Castle Dome (L. red dot) and a smaller dome (under 2nd red dot) are visible behind a shorter range 
of mountains near our RV park at YPG;  photo taken across a lake at the Laguna Conservation Area.

Castle Dome held a certain fascination for me both this winter and the winter four years ago when we stayed at Imperial Dam LTVA. Like seeing Pike's Peak or some other prominent mountain in the distance, I wanted to climb the doggone thing -- just because it was there.

The hiking/climbing websites I read, including this one by SummitPost.Org, indicated the most-used trail up the mountain is less rugged than it appears in photos or from the ground. The description sounded like a peak I could climb this winter.

However, that just didn't happen. My problem was not being unable to handle the trail to the top of the butte; it was the difficulty of reaching the trailhead!

I'll explain why in a little bit. First, let's talk about this huge wildlife refuge. You can enjoy it without ever worrying about how to climb Castle Dome if that's not your thing.


"Kofa" is an acronym for the "King of Arizona" gold mine, a notable mine in the area. Land that is now part of the refuge supported numerous gold, silver, and lead mines in the early 1900s.

Some of the abandoned mines and buildings can still be seen at the refuge, such as this museum along Castle Dome Mine Road in the southwestern corner of the refuge. The museum includes some old restored buildings from the former mining town named for Castle Dome:

This map I used in the last entry shows the location and relative size of the three national wildlife refuges in far southwestern Arizona.

I marked the city of Yuma in yellow, bottom left, and the approximate location of our RV park on the sprawling Yuma Proving Ground with a red dot. Number 1 = Cibola NWR, #2 = Imperial NWR, and #3 = Kofa NWR:

Kofa NWR is the most primitive of the three wildlife refuges, in part because it so big, so rugged, and so dry (no river running through this one). The visitor center and refuge HQ is located in Yuma, not even on the refuge itself.

There are several roads through the refuge, which you can see on a USFWS map online. It's also in a printed brochure that you can get at one of the refuge entrances or the visitor center.

Here's a small version of the map. I marked the road in yellow that we took into the refuge for about 15 miles and didn't get as far as Castle Dome, which I also highlighted in yellow. That should give a little perspective re: the size of this place:

Roads in the refuge are marked with solid or dotted lines.

Most of the roads are not maintained and are passable only with high-clearance 4WD vehicles like utilitarian Jeeps or ATVs.

In addition, there are no facilities on the refuge for drinking water, food, toilets, gasoline, or towing, if you get stuck in the sand or on a rock. Nor is cell phone coverage available everywhere or with every carrier.

And watch where you step. This area adjoins the Yuma Proving Ground and was used for desert training exercises conducted by General Patton during WWII. There is the danger of unexploded ordinance lying about.

You're pretty much on your own in this place! It puts the "wild" in "wilderness."


Activities for visitors include sightseeing, wildlife observation, photography, hiking, rock climbing, mountain climbing, cycling/ATVing on established roads, primitive camping, horseback riding and the use of pack animals (mules, burros, llamas), hunting in season, stargazing, and rock collecting at the Crystal Hill Area in the northwestern part of the refuge.

Some areas within or adjacent to the refuge boundaries are private. In the example below, you can continue along this road from one section of the refuge to another but you need to remain on the road until you're past the private property, which belongs to a mining concern:

The sign reads, "Hull Mine: Private Property. Leaving Refuge. No Hunting or Shooting.
No Parking on Road. Armed Patrols."

With a 2WD vehicle you can drive on five paved or well-packed, relatively smooth unpaved roads that come in for a few miles off US 95. The only one we've driven on is Castle Dome Mine Road. It goes about ten miles to the museum I mentioned, then narrows and gets rougher before it reaches Castle Dome Mountain in another five miles.

You can see more of the refuge if you have a high-clearance vehicle, 4WD, ATV, motorcycle, or bicycle. Several rough or sandy roads access various mountains, rock formations, springs, wells, horse tanks, mines, and cabins.  

To access the vast majority of this refuge you need a horse, however, or be prepared to do a lot of hiking or running on your own two feet. A whopping 80% of it (5,323 acres) is designated wilderness -- and you can't even ride a bicycle in the wilderness.


The refuge was established in 1939 after an extensive campaign by the Boy Scouts of America to protect the unique desert bighorn sheep who live here. Somewhere between 400-800 sheep presently live on the refuge, per the official brochure.

Some other wildlife species that live here include desert mule deer, desert kit fox, bobcats, mountain lions, badgers, bats, squirrels, mice, desert tortoise, white-winged doves, Gambel quails, golden eagles, Gila monsters, desert lizards, iguanas, various snakes, and other birds, mammals, reptiles, and  amphibians that have adapted to harsh, arid desert conditions.

Teddy Bear cholla cacti; barbed wire indicates private property/no trespassing.

Typical Sonoran Desert cacti, including Saguaro

A wide variety of plant life that has adapted to these same harsh conditions also thrives in the refuge. Two of the more unique plants are Kofa Mountain barberry, a rare plant found only in southwestern Arizona, and the California fan palm, the only native palm in Arizona.

About 100 of these palms are located in Palm Canyon (aptly named!) on the west side of the refuge. Palm Canyon Rd. is located at about Mile 85 on US 95. We did not visit there.


We made several mistakes when we visited the Kofa NWR on January 2 and it ended up being our only trip up there from our RV park at Yuma Proving Ground. Although the refuge borders many miles of YPG, the base is larger than the refuge and even the closest entrance into the refuge was a good distance from our camper.

The first mistake was not leaving to go up there until after lunch. We  didn't have enough hours of daylight to complete our "mission." The second mistake was taking the Odyssey minivan and not the truck, which isn't 4WD but has higher clearance.

Zoomed in on Castle Dome from the most southern paved entry road into the refuge

Our goal that day was to see if we could get back to the trailhead for summiting Castle Dome. I wasn't planning to hike up it that day but I wanted more information to better plan my intended hike. Since we'd read that the road is suitable only for a 4WD vehicle to get all the way to the trailhead, we took our bikes and thought we'd ride them past the point where the minivan couldn't go.

I also wanted to eyeball the route up the butte, which is on the north side of Castle Dome, not the side we've been viewing from the southwest that looks very intimidating to climb.

Above and below:  Three domes are visible in these shots from the gravel road before the museum.

We drove up US 95 to Castle Dome Mine Rd., which is the most southern entrance to the refuge.  The first mile is paved, then smooth dirt/gravel another nine miles to the Castle Dome Museum, site of the mining ghost town mentioned above.

We parked to see what's there. Visitors can tour some old buildings or go on a half-mile walk to see part of the old mine area ($10 each).

Since that wasn't our goal for the afternoon, and we've done enough mine tours previously, we passed on this one.

We drove only about half a mile past the museum before turning around.

The road was smooth enough to drive farther than that with the minivan but it was very narrow -- a problem if someone was coming the other direction -- and there were no pull-offs to park so we could get out and ride our bikes the rest of the way to check out the road conditions.

About half a mile north of the museum we found a place where we could (barely) turn around. We drove back past the museum and parked two-thirds of a mile south of it at a pull-off on public land. The museum is on private property and we didn't want to risk getting towed since we hadn't paid the museum fee.

We rode our bikes back to the museum, then 3.1 miles north of it before getting tired of all the rough rocks and some deep sand. Neither of us was having much fun and my cyclo-cross bike isn't built for these conditions. We were still a couple miles from the trailhead but out of time and motivation to continue.

I took the remaining photos north of the museum while riding our bikes:


Above and below:  The road looks smooth here but it's quite narrow.



We had a different perspective of Castle Dome as we ventured northward, seeing it more from the west.

From that direction, it appears there is more of a "slope" to the top of the butte and not just the steep vertical rise visible more from the south:


We could drive the car a couple miles north of the museum and try to find a spot off the road to park it. Past that is a deep ravine. That's probably still too far for me to walk in daylight to the trailhead (at least another three miles on rough road), up and down the mountain, back out to the car, AND drive 12 miles of narrow, unpaved road.

Note that even a 4WD truck would have problems with the rock ledges in one of the washes where we had to walk our bikes. I wouldn't advise taking a very nice truck out there. An ATV is the most sensible mode of transportation to continue farther north on this road.


At our turnaround point, already tired of the rocky road conditions, Jim looked at the rugged west side of Castle Dome and asked me if there are ever times I say to myself, "Sue, you're 66 years old. Aren't there just some things I shouldn't do anymore?"

I laughed and said, "Rarely!"

From the south and southwest, Castle Dome looks impossible to climb without ropes and other gear but from the north, where the main trail goes up, it's -- reportedly -- possible for fit hikers to reach the top. Challenging, according to the website descriptions I've read, but doable.

We didn't see Castle Dome from that side so I still don't know what the trail is like. Rats.

I'm frustrated that I can't even try to climb it. I'd need an ATV or basic Jeep to get out there. Four ATVs passed us outbound while we were cycling and I was wishing I could hitch a ride.

It's not even practical for me to drive out as far as I can in one of our vehicles and walk from there. The total distance out and back on the road and to the top of the butte is too long to do in daylight in the winter, and while riding our bikes we didn't see anywhere closer to the trailhead to park.

There were some pretty cool cloud formations that day.


I gave up the idea of climbing Castle Dome this winter. We never did go back up there to visit other parts of the refuge, like Palm Canyon, which were farther from our RV park.

I'll keep Castle Dome on my list of "Maybe's" if we ever spend the winter at YPG again. Maybe we can rent an ATV?? I hate to just give up.

Next entrya long winter car trip from warm Arizona deserts to snowy Montana mountains and back

Happy trails,

"Runtrails & Company" - Sue Norwood, Jim O'Neil, Cody the ultra Lab, and Casey-pup

Previous       Next

2016 Sue Norwood and Jim O'Neil