MARMOTS: there is no concern about marmots chewing car engine hoses except in early summer. You can ask a ranger to confirm this, as I did.
Although the road is only one lane wide in a few spots, if you go no faster than 15-20 miles per hour, stay on your side of the road, and look ahead to see cars coming, chances are there will be a turnout where you can stop and wait for them to go by.
My husband drove our 4Runner up to Atwell Mill Campground on Friday, September 16, 2011 around 1:30-2:30 p.m. We never had to back up to let another car go by. We encountered maybe six cars coming down, either at wide enough spots or we could see each other soon enough for one or the other car to wait in a wide spot.
The 23-site (or is it 24?) campground had only about four-five sites occupied on Friday night, only two on Saturday night, and between Saturday and Sunday we saw only a few sluggish mosquitoes, seven deer (strolling through the campground) and four bears (two strolling separately through the campground, one running away from the trail, one crossing the Mineral King Road)!
When you start going up Mineral King Road, the road is essentially never straight. It constantly turns right or left. The driver must constantly be turning the steering wheel, right, more to the right, more to the right, left, more, more, right, left, right, left, etc.
The road width varies between two narrow lanes and one narrow lane, every few breaths. It gets wider between the National Park entrance and Atwell Mill Campground.
Visibility varies from seeing the road a few hundred yards ahead, to blind, one-lane curves around steep rocks. After one such turn, we found a cow standing on the road's right edge, against the cliff, grazing.
Although there are no guard rails, the edge of the road is never precipitous. There are often grasses, bushes, and trees along the road's edge that make it look even less steep. See photos.
To see how the road never goes up or down steeply, see photos.
If I had to drive on this road, I would likely go at 15 (not 20) miles per hour, so it would take me more than an hour, therefore the challenge for me would be to maintain such intense alertness and precise responsiveness for that long.
On Sunday we drove on (up) to Silver City and the campground beyond. The road was narrower more of the time. On the way down to the bottom of Mineral King Road, we encountered about three bikers pedaling up.
- Compared to road #30 (Honoapiilani Highway to the west, Kahekili Highway to the east) around the northwest coast of Maui, Mineral Kind Road is easier because it lacks sections that are simultaneously narrow, steep, and long--especially when you have to back all the way down a long, steep, one-lane slope to let a pick-up truck go by!
- Compared to Road 612 to Bjargtangar, the westernmost point in Iceland (and Europe), Mineral King Road is much easier. Road 612 in Iceland doesn't have steep grades, but it is narrow, unpaved, loose gravel, along a steeper cliffside, half-way between ocean and sky. Driving west requires driving along the ocean side of the road, with locals barreling down the other way. I drove an SUV out that way and was scared the whole time--thank goodness it didn't take very long!
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.