SH-16 was not extended beyond Beggs until 1954, when it was extended east to US-62 and US-64. This section of gravel highway had a slight jog to the north, causing it to meet the U.S. highways at Jamesville, north of the present-day junction. The following year, SH-16 was extended even further east, passing through Muskogee via US-62, US-64, and US-69, and proceeding along its present-day alignment to Okay. In Okay, the highway turned east, following present-day SH-251A across Fort Gibson Dam and coming to an end at SH-80. This extension was entirely paved.