Blondie encouraging Tuco, The Good, The Bad & The Ugly (1966)
The United States Forest Service (USFS) categorizes the roads within its boundaries as "Primary Routes," "Secondary Routes," or "Low Standard Routes." That's it. Just three categories for the staggering variety of roads in the backcountry, even just here in the Black Hills National Forest.
Well, it's a start. Here's a USFS graphic introducing each category of roads in our National Forests.
As an introduction to understanding these categories of roads in the Black Hills, here are some of my general observations, with representative photographs. Whatever the USFS calls them and however I describe them, every road in the Black Hills will deliver a variety of riding conditions and challenges that change over time. Your eyes on the road and tires on the ground are the best way to know these roads.
Note that the USFS manages extensive logging operations in selected parts of the Black Hills. In large part, that's why most of these roads exist. Yield to all traffic out there, but especially the big logging trucks. And be thankful to be able to ride on the seemingly unlimited roads resulting from their work.
The Good (USFS Primary Route)
The most developed non-paved road in the USFS system is the Primary road, which is designed, built, and maintained for year around, regular travel by standard passenger cars. In the Black Hills, the surface of these roads typically is moderately graveled, hard packed local dirt and limestone that drains water well and generally does not instantly clog, at least not like Iowa top soil, Nebraska talc, or Oklahoma clay. Some roads are treated with Magnesium Chloride, which hardens and stabilizes the surface.
Primary roads generally are wide enough for opposing motorized traffic to pass easily. If enough gravel exists to form tracks, there would be three or even four. Often a small shoulder will accumulate a bit more gravel that has been pushed off to the side. Relatively high speed vehicle traffic may create washboards and pockets of loose gravel in spots, especially around curves and corners.
My ride of choice for Primary roads is my Black Mountain Cycles Monster Cross bike with 40 mm Schwalbe G-One tires. Even when loaded for multi-day bikepacking, the Black Mountain provides plenty of support and control to comfortably ride all day. Relatively speaking, these gravel roads are fast.
On USFS maps and signage, a Primary road is designated by brown sign with a number enclosed in a rounded corner, isosceles trapezoid having the longer parallel side on top, as shown below for Boles Canyon Road (117).
The Bad (USFS Secondary Route)
The next level of developed, non-paved roads in the USFS system is the Secondary road, which is maintained for high clearance vehicles. In the Black Hills, Secondary USFS roads typically are similar in composition to Primary roads, that is, hard packed dirt and limestone that handles water well and does not overly clog. However, the surface may be even less graveled, or just occasionally graveled, or not graveled at all. Almost certainly, it will not be treated with Magnesium Chloride. Foremost, that means Secondary roads are more susceptible to mud when wet and ruts when dry.
Due to less maintenance, Secondary roads also sport occasional loose dirt, exposed surface rock, pot holes, standing water, and fallen timber, while presenting sharper turns, steeper gradients, and shorter sight lines. Also, Secondary roads typically are two tracks wide, often with little to no shoulder. If a motorized vehicle approaches, I typically pull off the road to allow it to pass. For logging trucks, I definitely leave the road.
All that being said, many Secondary roads in the Black Hills are passable in dry weather in passenger cars, if attentive to occasional obstacles and clearance issues. For example, I confirmed my cue sheets for the entire Black Hills BackBone route driving my 2006 Chevrolet HHR, hardly a high clearance vehicle. Over the 310 mile route, with many miles of Secondary roads, I maneuvered around a few high-center issues and only had to skirt one fallen tree blocking the road. These roads can be fast, but stay alert.
My ride of choice for most Black Hills Secondary roads is still my Black Mountain MonsterCross with 40 mm tires. These roads may be rougher and mountain bike type gearing may be helpful in spots, but most of these roads are developed enough for me on that "gravel" bike. On the other hand, if loaded for a multi-day ride with significant miles of Secondary roads, I may well opt for my Jones 29+ with bigger tires.
On USFS maps and signage, a Secondary road is designated by a three or four digit number enclosed in a brown, rounded corner rectangular sign, as shown below for Williams Draw Road (691).
The following photographs show three USFS Secondary roads in the Black Hills.
The Ugly (USFS Low Standard Route)
The third level of developed, non-paved road in the USFS system is the Low Standard road, which is unimproved and not maintained for automobiles. The Forest Service recommends travel by vehicles with both high clearance and four wheel drive. I would add driver prudence and experience.
Design, construction, and maintenance of Low Standard roads are all over the map, even along a single numbered road. Some sections may be soft dirt, while others are rock gardens. If wet, standing water and mud can be a real issue, leaving deep ruts when dry. Maybe a load of chunky rock was dumped to stabilize a low spot, or maybe not and there's a stream to ford. They are rough, sometimes little more than a bull dozed logging trail. For me, this is mountain bike territory, for tires and gears, even unloaded, for anything more than a short connector.
Many, many, many are dead-end spurs that were built to get to a spot for logging. Maybe some spurs later connect to something else and haven't made it on a map, or maybe not. I often refer to the USFS Motorized Vehicle Use Maps, which are updated every year and prove to be pretty accurate. However you navigate, count on no cell coverage and no passing traffic of any kind. You are on your own.
If you like this kind of riding, the Black Hills offer a lifetime of miles to explore.
On USFS signage, a Low Standard road is designated with a three-digit number vertically imprinted on short, 4 inch wide, brown carbonite post. On USFS maps, it's just a plain three-digit number. The designation of any road emanating from that Low Standard road adds a decimal and another number. For example, in the Black Hills, USFS 278.1 runs off of USFS 278. Then, any roads running off of USFS 278.1 get letters, the first being USFS 278.1A, then 278.1B, and so on. It can be confusing in the field and USFS map navigation is an entirely separate subject. Just know that any carbonite USFS road sign with a three-digit number, or with decimal numbers, or with letters, identifies a Low Standard Road.
Shown below is a sign for Low Standard road 242, and then one for Low Standard road 325.1D.
The following photographs show a sampling of USFS Low Standard roads in the Black Hills. I captured all of these images while riding, with the sole exception of the last photograph, which Lucas Haan provided as an example of a deposit of chunky gravel. I included more photographs of Low Standard roads because of their great variety.
The Good, The Bad And The Ugly, Danish National Symphony Orchestra (2018)