The portion of MD 17 north of Wolfsville was brought into the state highway system in 1956, the same year the Myersville–Middletown Road was transferred to county control.

The roadway continues into Loudoun County, Virginia, as SR 287 (Berlin Pike), which heads south toward Lovettsville.

The bridge's northern end lands just south of a roundabout that connects MD 17 with Petersville Road, Maryland Avenue, and both directions of B Street.

[1][2] MD 17 heads north from the Brunswick Roundabout as two-lane undivided Petersville Road, which climbs out of the narrow Potomac River valley.

North of US 340, the state highway runs mostly straight through farmland parallel to the upper reaches of Little Catoctin Creek intersecting with Brentland Rd.

and then Lee's Lane following which the highway passes through a pair of right-angle curves and parallels South Mountain to the hamlet of Coatsville.

The state highway intersects Old Hagerstown Road at an oblique angle and crosses Catoctin Creek again before veering north and reaching Ventrie Court, which heads east to provide access to a park and ride lot serving MTA Maryland commuter buses.

The road temporarily expands to a four-lane divided highway for its diamond interchange with I-70 at the town limit of Myersville.

After reducing to two lanes, MD 17 continues as Main Street toward the center of town, where the state highway turns east onto Wolfsville Road.

[1][2] MD 17 heads north into a mountainous area with a mix of farmland and forest at the northern end of the Middletown Valley.

Harp Hill Road is a straighter but much steeper alternate route between Ellerton and Wolfsville compared to MD 17, which parallels Middle Creek and crosses the creek thrice as it winds through the communities of Crossnickel and Middlepoint and passes the historic Peter of P. Grossnickel Farm.

Another section of the highway was planned to follow the alignment of Old Hagerstown Road south from the Myersville segment to the National Pike west of Middletown.

Other segments completed that year included a macadam stretch from Coatsville to Burkittsville and a concrete road from Arnoldtown to the National Pike in Middletown.

By that year, the gap between Burkittsville and Arnoldtown, Main Street in Myersville, and Wolfsville Road from Ellerton to Grossnickel had been paved with concrete.

In addition, a macadam road was constructed from Main Street in Myersville to the first crossing of Middle Creek north of the town.