Posts by Mark
There are three fluids in your car that contain water: the battery electrolyte, the washer fluid, and the coolant. Everything else is hydrocarbon-based, and in a properly-functioning car, contains...
For reasonable values of "trail", "parallels", "navigable", and "river", the Washington and Idaho Centennial Trails run 59 miles from Higgens Point on Lake Coeur d'Alene to Sontag Park on the Spoka...
The easy technique is to simply hold the spear in your hand with the tip under the water and stab the fish. Once your spear enters the water, refraction has identical effects on your view of the s...
While out hiking today, I came across a spot where someone had fired off a couple dozen shotgun shells, then left the spent cartridges lying around. Dealing with those was simple (put them in my t...
Look under the bridge for cracked or rotted beams -- in particular, cracking in the middle of the bridge, or rotten wood at the ends. If the bridge is more sophisticated than a deck nailed on top ...
At a guess? A change in architecture. Pigeons favor cliff ledges as nesting sites; they'll happily build nests on window ledges as a substitute for natural cliffs. Sparrows favor cavities: tree ...
The presence of a ford in a river is a local condition: it's a point in the flow where the river has leveled out, producing a wide, slow, shallow flow. In addition, a ford generally has a hard bot...
I'm not familiar with the Wichita refuge; my bison experience comes from the Yellowstone area. That said, I would never describe bison as being particularly "active": they spend most of their time...
The big risk in geyser basins is that you can't see what's going on underground. There are often latent hot springs or fumaroles: areas where hot water or steam has eroded the ground almost all th...
It's called the "mountain climber's weight loss program": eat everything you want, and climb two mountains a week. Serious rock climbers aren't fat because they can't eat enough to get fat. Climb...
For any reasonable depth (ie. something you'd be willing to dig without specialized machinery), a deeper hole makes for a more stable temperature. The extra mass of soil surrounding your cellar ac...
It depends on the nature of the deficiency. The most common form, red-green colorblindness, isn't a problem: I'm not aware of any situation where color coding is used to convey safety-critical inf...
In the Grand Canyon, it's because it's easier for a human to get off the trail than it is for a mule. I suspect the same reasoning applies in most places.
I've just 3d-printed what's supposed to be an ear-shatteringly loud emergency whistle (120 dB at one meter). However, it's apparently somewhat sensitive to printing conditions, because some people...
The crime rate on most trails is 0, due to the very low frequency of use. The trails that have had a crime committed on them tend to have a very high crime rate, again due to the low frequency of ...
Most of the time, the "Known to the State of California" warning is an incantation to ward off lawyers. That's not true for fuel. White gas/Coleman fuel/whatever-it's-called has significant amoun...
For the specific question of drifting on the Great Lakes, doing so is effectively suicide. First, there's the matter of traffic. The Great Lakes are a major shipping lane, with upwards of a hundr...
Since you describe it as "near your residence", it's probably what is known as an "urban micro": a small, camouflaged container attached to something like a street sign or a lamp post.
For the most part, your list looks reasonable for traditional (ie. non-ultralight) backpacking. The most important thing now is to get the pack fitted and balanced properly, and then get used to m...
His filter has basically two stages: A series of mechanical filters (coarse rocks, fine rocks, coarse sand, fine sand) to remove macroscopic contaminants (eg. dirt) from the water. By using seve...
Zion has only one unpaved road you're likely to want to drive on: a one-mile stretch of the Lava Point road. That road is marked on the map as "impassible when wet", which I suspect means an SUV w...
Some mountains change height at a surprisingly fast rate. For example, the magma chamber beneath the Yellowstone caldera is currently inflating. This is causing some of the nearby mountains to gr...
Some back-of-the-envelope calculations: 12 volts * 4 amps = 48 watts * 8 hours = 384 watt-hours. That's the minimum battery capacity you'll need to power this for a night. The Goal Zero Sherpa 5...
If you were the only visitor to the area, the lowest impact would be to defecate on the surface and leave it. Few animals bury their waste, so natural disposal has evolved around dealing with surf...
If your vehicle has a closed metallic structure, you are definitely safer inside than out: if lightning strikes your vehicle, or near your vehicle, the metal will conduct the electricity away from ...
