This map depicts the area east of Marriottsville, with McKeldin Falls at the center. The dashed blue line shows the pre-diverted route of the Patapsco River, the green the original 1830 alignment of the railroad.

With the shift of the river, Howard County grew slightly larger at the expense of Carroll County.

As we head west and approach McKeldin Falls, the small hillside cut at left is the first evidence of realignment: during the intial construction of the line circa 1830, workers had little more than hand tools for exacavating and so had originally veered the tracks to the right around that rocky obstacle.

The utility poles still follow that original alignment and illustrate how it had swung wide right before crossing left just ahead. Cutting into the rock at left came years later.

At this spot the current alignment now crosses the original which had proceeded left between the two clumps of older trees to hug the south bank of the river.

The year the original was bypassed remains uncertain. I suspect 1838/1839 since 1) other realignment work, such as that at Elysville/Daniels, was being done at that time, and 2) the project's redirection of the Patapsco River is noted in the 1855 book "Rambles in the path of the steam-horse" by Eli Bowen (page 165). The book can be read online.

Non-leaf season is your best bet to see a stretch of the mounded earth of the original alignment (topped by the green line). Left of center note the gap in the mound where the alignment had crossed what had been the natural route of the Patapsco River.

Same vantage point as the prior photo except turned to look right (west). The straightening effort cut the original alignment's roughly 0.5-mile length down to about 0.4 miles.

Barbed wire encrusted with a century or more of rust warns state park hikers of the lack of a bridge ahead.

B&O likely removed and recycled the stones of the (arched?) bridge formerly here, though not into the then-new/current alignment's bridge in the distance (bridge number 23) because it was under construction while the original was still on duty.

From a swampy location between the original alignment and the present one, at bridge 23 Dave caught Union Pacific 6340, a so-called "patch unit", displaying hasty renumbering and only partial repainting from its days as Southern Pacific 305.

The swamp marks the remains of the Patapsco River's original route. The stonework here matches that of other arched bridges built during the OML's period of tunnelling and realignment between 1900 and 1905. The 1855 book "Rambles in the path of the steam-horse" specifically mentions the lack of a bridge here, which suggests it was added later, perhaps to facilitate drainage of the Patapsco's natural route.

The falls is located straight ahead on the other side of the tracks.

Hang eight? Yellow and red boxcars of eastbound mixed freight brave the rapids of McKeldin Falls, the largest on the Patapsco River. Here the river drops 12 feet in 60 feet, producing a 20% "grade"; the railroad's maximum grade west to Mt. Airy is 0.7%.

The B&O-created falls is named for Theodore McKeldin who served two terms as governor of Maryland sandwiched between two terms as mayor of Baltimore. There's a certain ironic twist: McKeldin was a supporter of transportation, but emphasized roads, planes and ships over the railroad.

Link: American Whitewater

Back on the south, original-alignment side of the falls, the forest's green spring growth can't hide the mound on which the railroad had traversed. Ahead is a break in the mound where it appears a box culvert may have been.

At the break in the mound, Dave found this stone, surprisingly little evidence of a box culvert. He writes:

"My theory is that the man-cut stone pictured indicates a culvert at this spot. There is another break very close to this one, and I think maybe that one could be a washout caused by heavy water flow, since I couldnt find any man-altered stones there. But I think where this stone is, there used to be a stone culvert. I think the stone is proof of a now-dismantled culvert or small arched bridge."

Evidence something railroad this way comes, or came, is this now-dislodged stone stringer that perhaps wishes to return to the active trackbed days of its youth.

Horses of the non-iron variety keep clear a path along the top of the original alignment.

Eventually the surviving shelf of the original, disused alignment bends back close enough to see the current.

Now we're looking back from the western end of the disused alignment, with the Patapsco River just off photo-left. Prior to this stone wall blocking its natural route, the river proceeded toward the utility pole at middle left, and the railroad had followed the bank to the right.

Anyone not fond of snakes would best avoid this wall as many of those slithery creatures seem to enjoy resting within the gaps between its boulders.

The small gap in the forest overgrowth at picture center marks the emergence of the original alignment. The river-diverting wall is unseen on the left.

Dual mileposts 24 stand where the original and current alignments join and continue west to Marriottsville.