Three days walking the spine of South Mountain — past the country's first monument to George Washington, over a Civil War battlefield, and down to a stone arch built for dead war reporters. One camp, two nights, hot showers.
Live from Open-Meteo, refreshed every time this page loads. Mid-August on this ridge means humidity, not altitude, is the enemy — watch the feels-like number, not the air temp.
Tap any marker for details. Toggle the layers below to filter what you see. The trail line is hand-traced for orientation — load a real GPX into FarOut or Gaia before you go, and don't navigate off this.
11174 Baltimore National Pike
Myersville, MD 21773
39.53555, -77.60378
Both cars live here for three days. Arriving Friday morning dodges the weekend scramble — this lot fills by mid-morning on summer Saturdays. No restrooms here; last real bathroom is wherever you stop on the drive.
MI 5.2 · 1,020 ft
Free, first-come first-served, no reservations. Spigots, flush toilets, hot showers, bear poles.
MI 12.3 · 950 ft
War Correspondents Memorial Arch, stone barn ruins, potable water, real bathrooms.
Mileages here are corrected against Appalachian Trail Conservancy section data — they run longer than the original draft. Day 2 has a short and a full version; decide that one at breakfast based on heat and how everyone's feet feel.
South Mountain is a dry ridge. Almost everything reliable is at a road crossing or a state park, not in the woods. In August heat plan on a litre every 90 minutes while moving — that is more than it sounds like.
| Source | Where | Reliability | Notes |
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Dahlgren to Gathland is 7.1 miles with nothing dependable in between. Rocky Run and Crampton Gap shelter springs both go low or dry in late summer. Leave camp on Day 2 carrying 3 litres each, minimum — and refill fully at Gathland before turning around.
Spigots at Dahlgren and Gathland are treated municipal water — drink straight. Springs, seeps and Rocky Run get filtered, no exceptions. Back-flush the Sawyer at camp both nights; silty late-summer water clogs it fast.
On 14 September 1862, roughly 28,000 Union and 18,000 Confederate soldiers fought for control of three gaps in South Mountain. Your route crosses all three. Three days later the same armies met at Antietam, eight miles west — the bloodiest single day in American history.
Tick items off as you pack. Your progress saves on your own phone, so everyone can track their own list independently.
Tent body / poles / fly across two packs. One stove and one pot per pair, not per person. One water filter per pair plus one spare for the group. Four separate first aid kits is three too many — carry one good one and a blister kit each.
Two dehydrated dinners for four, prepped at home. Both rehydrate in the pot with a cozy — no simmering, no fuel wasted.
The Old South Mountain Inn sits at Turners Gap, a four-minute walk from your tent — it has been feeding travellers on this pass since 1732 and is used to hikers walking in filthy. Rasco NY Pizza in Boonsboro will also deliver to the Inn's parking lot. Consider night two.
26 lb, part shepherd, a real snout, and plenty of trail miles already behind him — Louis is far better equipped for this than the average pug. Conditions are on his side too: mid-80s at around 55% humidity, a canopy over nearly the whole route, and no schedule to beat. The plan is sound. What follows is about keeping it that way.
Even with a decent muzzle he sheds heat mostly by panting, and panting works worse as humidity climbs. So his ceiling is set by temperature and pace, not by distance — fourteen shaded miles at a conversational pace with frequent water is easier on him than six rushed miles in open sun. Day 2 is the one to watch: if it runs hotter than forecast, take the short version rather than pushing the full 14.2.
If it happens: stop, get him into shade, pour cool — not ice cold — water over his belly, groin and paws, and offer small sips. Ice water constricts surface vessels and traps heat inside. Don't restart the hike that day. If he isn't visibly better within about fifteen minutes, drive out and find a vet.
Carrying him is a legitimate move and worth doing early rather than late — the moment you're wondering whether to, is the moment.
Every gap on this route crosses a paved road, so you are never more than about 3.5 miles from a place a car can reach you: US-40 (start) · Boonsboro Mtn Rd · Monument Rd · US Alt-40 at Turners Gap · Reno Monument Rd at Fox's Gap · Gapland Rd at Crampton Gap. Leave a copy of this itinerary with someone at home.
A real 5×5 card with a free square in the middle. Tap one when someone in the group gets it; complete any row, column or diagonal to score a line. Saves on your phone, so you can each run your own card — first to three lines gets bought the post-hike burgers.
Download the offline maps in Gaia or FarOut before you leave the parking lot. Cell data on the ridge is a coin flip.