The so-called "mansion" is...
The so-called "mansion" is a two-story concrete house with an outside stairway and no glass. We didn't explore the nearby mine shaft for safety reasons.
The BLM's Adopt-a-Trail Program is alive and kicking in Arizona. Proof of that is in Mohave County in the northwestern portion of the state. Just a few miles southeast of Kingman and a couple thousand feet higher, you will find the Moss Wash Trail. Moss Wash gets its name because of the moss growing along its bottom from a year-round spring. The Moss Wash Trail leads to the Hualapai Mansion (known locally as the Moss Mansion) and the Gold King Mine. Built in the 1930s during the Great Depression, the mansion is two stories tall, built of 6-inch-thick reinforced concrete, and has high arched windows (now missing all the glass). Built to house the owners of the nearby Gold King Mine, the Hualapai Mansion has been adopted by the Walapai 4 Wheelers, who attempt to keep it graffiti- and trash-free. The Gold King Mine must have been a bust because it only amounts to a 180-foot tunnel and a shaft of 50 feet, so the mansion was soon abandoned.
We used the Hualapai Mountain Lodge as our "jumping off" place. To reach this point simply follow Hualapai Mountain Road (County Road 147--which is also Stockton Hill Road at Interstate 40) southward out of Kingman and up into the Hualapai Mountains. Continue following the road past the Hualapai Mountain Park (open to camping) and the Hualapai Mountain Park Ranger Station to the lodge. At the lodge you'll be able to start the day with a hearty breakfast and, if you ask nicely, possibly leave your tow vehicle in the parking lot while you're out on the trail.
Because of the equipment needed to build the forms, mix the concrete, and build the house--not to mention digging the Gold King Mine--I'm assuming that at one time there was a road into the mansion, but not now. In fact, the trail has changed since my first trip there four years ago, and will probably continue to change with every storm system that blows through.
Drop your air pressure at...
Drop your air pressure at the trail head to increase your traction. From here on to Blake Ranch Road you'll need four-wheel-drive.
Do not attempt this trail alone or in a stock vehicle. I would rate the trail up Moss Wash at a 3.5- to 4-difficulty, so you'll need some kind of traction enhancement in at least the rear differential (a front locker would be even more help), a modest lift, and at least 33-inch aggressive off-road tires. Other than the trail through the Moss Wash streambed, the trail is more like a 1.5- to 2-difficulty, although there are some fairly steep hills and deep wash-outs.
If you want an all-day trip, with lunch at the mansion as we did, you can start the trip from the lodge. If you'd like a shorter trip, with just a 6-mile roundtrip from pavement, you take I-40 east out of Kingman to the Blake Ranch Road. Follow Blake Ranch Road south to the unmarked Moss Wash Road (N 35 01.33/W 113 48.47) and turn right. Follow the trail to the mansion, approximately 3 miles. The mansion's coordinates are N 35 01.59/W113 50.22. You can then turn around and return to Blake Ranch Road or do the reverse route of the trip we took.
Back at the lodge, continue southward along the road to Flag Mine Road, and turn right. Continue on the main road through several forks, past a burned area at the top of Moss Wash, to the BLM Moss Wash Trail sign. Here's where you'll want to drop air pressure, engage your hubs and four-wheel drive, and then drop into Moss Wash (N 35 01.53/W 113 53.41). Stay on the trail for about 2.5 miles, then take the left fork that follows Moss Wash. In about a half mile, you'll want to take the right turn and continue toward the mansion. Slightly over one mile from the turn, you'll find the mansion. For the return trip continue down the wash to Blake Ranch Road and turn left for I-40.
GPS Coordinates
Moss Wash Road intersects Blake Ranch Road:N 35 01.330W 113 48.470
BLM Moss Wash Trail sign:N 35 01.530W 113 53.410
Moss Mansion:N 35 01.590W 113 50.220

The BLM has marked the Moss...

The BLM has marked the Moss Wash Trail's trailhead with this sign. Watch for it.

Paul and Jamie in the Rock...

Paul and Jamie in the Rock Lizard lifted Cherokee negotiate the eroded trail.

Keith Stettner, who has a...

Keith Stettner, who has a for sale sign on his '76 CJ7 rock crawler, had no trouble with any of the trail.

A Jeep that is unfortunately...

A Jeep that is unfortunately becoming fairly scarce on today's trails, Ron Stover's '45 CJ-2A "flatty" was fun to watch, and brought back fond memories of the author's first Jeep.

Robert Fry's locked up TJ...

Robert Fry's locked up TJ easily traversed the trail.

Lunching in the shade of the...

Lunching in the shade of the mansion, and using the stairs for sitting because we forgot our chairs.

A stripped Willys Wagon was...

A stripped Willys Wagon was seen below the trail. It was determined some time ago that it couldn't be recovered safely so it rests there as a warning to drive carefully.

Every so often the trail would...

Every so often the trail would climb out of Moss Wash to offer views of the surrounding hills, then it would drop back down into the wash.

Reminiscent of the Burma Road...

Reminiscent of the Burma Road of World War II fame, the trail flowed in and out of Moss Wash.

The one non-Jeep on our trail...

The one non-Jeep on our trail ride was Marty Helton's 1972 Ford Bronco, which was being followed by the author's '82 CJ-7.

Abandoned mines and mine buildings...

Abandoned mines and mine buildings are found all along the trail. Perhaps this was a powder magazine at one time?

The rocks in the dry streambed...

The rocks in the dry streambed were minor obstacles for Keith's stripped-down CJ.

Keith Stettner almost laid...

Keith Stettner almost laid his CJ over on its side when he took a slightly different line than the rest of us.

Marty follows Keith over one...

Marty follows Keith over one of the rockier sections of the trail.

After lunch, we followed the...

After lunch, we followed the stream away from the mansion.

Jim and Pam Klopfer, in their...

Jim and Pam Klopfer, in their '89 Cherokee, dodge rocks and bushes near the mansion.

Being a bit wider than the...

Being a bit wider than the Jeeps, Marty Helton's Bronco barely fits between the rocks and the brush lining the trail.

It was near the end of the...

It was near the end of the trail after a very satisfying day on the rocks.

Another abandoned mine was...

Another abandoned mine was seen near the mansion, but we weren't close enough to determine what the structures were.