(Clackamas to Rock Creek Junction, Hwy #171 MP 4.91-8.15, 3.81 miles)
"Over the Clackamas Highway (common with OR224) from its junction with the East Portland Freeway, I-205, near Clackamas, to its junction with the Clackamas-Boring Highway near Rock Creek; thence easterly over the Clackamas-Boring Highway via Damascus and Boring to its junction with the Mt. Hood Highway, US26, approximately five miles west of Sandy. (Rev. 10/21/1980)"
~ ODOT, Descriptions of US and Oregon Routes, March 2007
OR-212 was designated at the inception of the secondary state highway system in 1935, running between OR-213 in Clackamas and OR-50 (future US-26) near Boring. At the time, the entire road was known as the Clackamas Highway #171. At some point in the 1950's, OR-212 was extended through Oregon City, West Linn, and Tualatin to King City; it was added onto OR-213, US-99E, and OR-43 from Clackamas to West Linn and it replaced OR-244 for the rest of the way. The portion between King City and West Linn was never in the state highway system; they were maintained by Washington and Clackamas County as well as the cities of Tualatin and West Linn.
At some point in the 1960's two things happened to OR-212: 1.) It, along with OR-213, was realigned to a new freeway section (a future section of I-205) between Clackamas and Park Place; and 2.) OR-212 was cosigned with OR-224 from Clackamas to Rock Creek Junction, resulting in the Clackamas Highway being moved onto OR-224 south of Rock Creek Junction all the way to Ripplebrook and leaving OR-212 on Clackamas County roads through Boring. The construction of I-205 was making OR-212 obsolete fast, and in 1979, the portion between King City and Clackamas, including portions along OR-43, OR-99E, OR-213, and I-205, was decommissioned, even though some maps continued to show the extended routing into the 1990's. As far as I know, there is no indication of former OR-212 along the former route west of Clackamas, and any indication of such that survived until today would truly be a roadgeek find.
Before OR-212 was shortened, the section between the OR-212/224 split and US-26 was maintained by Clackamas County until 1977. That year, ODOT and Clackamas County agreed to a jurisdictional swap, where state and local governments trade maintenance responsibilities of two highways. In this instance, the Clackamas County-maintained section of OR-212 became the Clackamas-Boring Highway #174, and the Canby-Marquam Highway #170 was transferred back over to Clackamas County.
Section 1 of this project will place the western portion of OR-212 on a sort of expressway alignment between Clackamas and the Rock Creek Junction. Due to the increase in traffic using OR-212 around I-205 for recreation (skiers headed to Mt. Hood), industry (truckers heading for the Clackamas Industrial Area), and residential (growth in Damascus), this section of OR-212/224 is one of the most congested in the state. This project would supposedly realign both OR-212 and OR-224 off of I-205 and the current section of the Clackamas Highway onto a new section. There would be interchanges at I-205 and at the OR-212/224 split with the possibility of a third interchange in the middle between 122nd and 135th Aves.
Section 2, which is more loosely defined, will increase traffic flow through Damascus and Boring to US-26.
There are two former sections of OR-212, but since there are three different combinations of routings, I decided to use three different colors when explaining the history of the route. Originally, OR-212 ran mostly as it does today, but instead of running to I-205 as it does today, it ran south along present-day Evelyn St., highlighted in red, to 82nd Dr. (historical OR-213) in Clackamas. Most of that routing is there, but an overpass across a railroad crossing is now the only means to connect Evelyn St. to 82nd Dr. today. This section lasted until the 1960's until the freeway was completed.
At some point in the 1950's, OR-212 was extended along OR-244's old routing to King City. This section, shown in green, ran along many different roads: First, it was duplexed with OR-213 along 82nd Dr. through Gladstone and Washington St. into Oregon City until it split off briefly at 14th Ave. before joining with US-99E in downtown Oregon City. It then joined OR-43 across the Willamette River to West Linn, after which it broke off and followed Willamette Falls Dr., Borland Rd., and 65th Ave. into Tualatin. 65th Ave. became Nyberg Rd. in Tualatin, which OR-212 followed until it jogged north on old OR-217 (also known as Boones Ferry Rd.) until Tualatin Rd., where it broke off of OR-217 and followed that road until its end at US-99W south of King City. Almost all of this section is still intact, save a section with at its junction with present-day OR-99W and a small section that was removed when Tualatin built a man-made lake near downtown in the mid-1990s. A bridge over the Clackamas River between Gladstone and Oregon City still exists, but is closed to automobile traffic.
When the first section of I-205 opened between Clackamas and Park Place in the 1960's, OR-212 was routed onto it. The section between Evelyn St. and I-205 is still OR-212 today, but the freeway section shown in blue only was OR-212 for a couple of decades, until 1979. When the freeway opened, the entire section shown in red and the portion of green from Evelyn St. to present-day I-205 Exit 10 was decommissioned. Some maps also say that OR-212 ran along I-205 all the way to Exit 9, but since the map was dated 1988 (when OR-212 had been decommissioned west of Clackamas), I don't know if that was ever the case.