OREGON INVENTORY OF HISTORIC PROPERTIES HISTORIC RESOURCE SURVEY FORM Note: For properties 35 years old and newer, starred (*) sections are the only required fields. *County: Clackamas *Street Address: *City Situs Address: 1850 North Shore Road Lake Oswego USGS Quad Name: GPS Reading, UTM Format (Universal Transverse Mercator): Lake Oswego Longitude: 122°41'13.32"W Latitude: 45°24'51.96"N Township: Range: Section: Block/Lot: Forest Hills #3 Tax Lot #: 21E 1E 9AC Lots 188, 189 190, 191, 1500 192, 193, 194 Historic Name: Grouping or Cluster Name: The Carl C. and Emma H. Jantzen Estate *Date of Construction: Other Names: House 1936 Boathouse 1931 Halvorson House Landscape 1931 Bridge 1931 Jantzen Estate Historic Use or Function: *Current Use: Associated Archaeological Site: DOMESTIC: Single Dwelling DOMESTIC: Single Dwelling Unknown Architectural Classification(s): Plan Type/Shape: Number of stories: House: Tudor Revival Asymmetrical 1.5 Bridge: Gothic Revival Boathouse: Gothic Revival Foundation Material: Structural Framing: Moved? Concrete Stud, masonry and coursed stone No Roof Type/Material: Window Type/Material: Multiple Hip; Flat/ possibly red slate tiles Multi-Light Casement Exterior Surface Materials Primary: Secondary: Decorative: Coursed Stone Two massive multi-flue chimneys; mock Hipped dormers, main entrance w2 wood half timbering, polygonal window bays lintel and ornamental door. Exterior Alterations or Additions, Approximate Date : House: Interior: The dining room and living room remain in original form; all other rooms were reportedly altered or suffered water damage and have been restored. Bridge: Original massive log beams were replaced by steel, wood skirt added to conceal framing, (prior to 1989) Boat house: None apparent Landscape: Non-historic gazebo and garden house added (prior to 1989); Stone terraces and paths added (1989); Roadway / driveway widened (ca. 2003); decorative rock walls added, one tree removed, entertainment area added, tram installed (ca. 2013); added a stream that flows through the garden in front of the house (date unknown); A 3,000 square-foot guesthouse was added to the property after 1987. A swimming pool was added prior to 1989. Number and Type of Associated Resources: Integrity: Condition: Local Eligibility: National Register Listed? Good Excellent On LDL Yes No Unknown Preliminary National Register Findings: Potentially Eligible: Individually or As a contributing resource in a District Not Eligible: Intact but lacks distinction or Not 50 years old or Altered - Choose one: Reversible/ potentially eligible individually or in a District Reversible/ ineligible, lacks distinction Irretrievable lack of integrity *Researcher/ Organization: Date Recorded: L. Radwanski/A. Boyd-SWCA Environmental Consultants: 1220 SW Morrison St. OR 97205. August 2014 City of Lake Oswego, 380 “A” Avenue, Lake Oswego, OR 97034 Additional research and review by Erin O’Rourke-Meadors SHPO #: Survey Form Page 1 of 15 Revised 12/02 OREGON INVENTORY OF HISTORIC PROPERTIES HISTORIC RESOURCE SURVEY FORM *County: Clackamas Street Address: City: Situs Address 1850 North Shore Road Lake Oswego Description of Property The Carl C. and Emma H. Jantzen Estate is located on a private island on Lake Oswego. The home’s official address in on North Shore Road, but the distance from North Shore Road to the edge of the lake is approximately 250 feet. Maps show this long drive as “Island Road.” The island is teardrop shaped and roughly 700 feet by 500 feet at its widest point. The island sits just south of the Lake Oswego Country Club. According to tax records, the island and drive from North Shore Road encompass 4.35 acres. The island is well landscaped, and a formal garden is located to the southwest of the home. There is no public right-of-way to view this home, so it was not formally surveyed. The City of Lake Oswego provided photographs from a recent site visit, which were used to describe the property. Public land use files also shed light on the home’s current renovations. The Bridge The home is accessed by a private bridge. The Gothic-style stone bridge has two square stone towers on the north non-island side of the bridge, both capped with red clay tile shingles. A wrought-iron gate can be closed between the two towers. The bridge is approximately 130 feet in length. It has wood log sides and a wood plank deck. The bridge is supported by four piers, which are set on a concrete foundation and are constructed of un-coursed stone on the upper two-thirds of the piers. The bridge has a wood skirt around the bottom edge to conceal structural framing. The 1989 cultural resources inventory shows that the original log beams were replaced by steel (Koler and Morrison 1989). It was at this time that a wood skirting was added to the edge of the bridge to conceal the newer materials. The wood plank boards on the deck appear newer, but no date could be found for their replacement. The Boathouse The boathouse is located to the south of the main house on the south end of the island. The single-story building has an L-shaped plan with a gable roof. A round tower is located west of the west façade. The roof is clad in red tiles. The 1989 cultural resources inventory described it as “red slate” (Koler and Morrison 1989). The building is constructed of rough-cut un-coursed stone, except for around the entrance door, which is set in irregular courses. An arched opening faces the lake on the south façade of the structure. A wrought-iron grate closes the arch. A smaller front-gable projection is on the east façade and houses the recessed entryway. The buildings floor is concrete, suggesting it is set on a concrete foundation. The Jantzen House The Jantzen House is located in the center of the island. After crossing the bridge, the driveway curves around the house to the east and past the home up to a garage on the west side of the house. A large grass lawn is in front of the house to the south. Mature deciduous and coniferous trees and ornamental plants are found on the island. Tax records show that the house is approximately 8,922 square feet and has four bedrooms and six bathrooms. The house has multiple sections. The center section consists of a wide hip roof with a front gable- on-hip projection. On the center section of the home are two hip-roof wings, one on the east and one on the west. *Researcher/ Organization: Date Recorded: L. Radwanski/A. Boyd-SWCA Environmental Consultants: 1220 SW Morrison St. OR 97205. August 2014 City of Lake Oswego, 380 “A” Avenue, Lake Oswego, OR 97034 Additional research and review by Erin O’Rourke-Meadors Survey Form Page 2 of 15 Revised 12/02 OREGON INVENTORY OF HISTORIC PROPERTIES HISTORIC RESOURCE SURVEY FORM *County: Clackamas Street Address: City: Situs Address 1850 North Shore Road Lake Oswego The center gable has a shed-roof dormer with a bank of leaded windows and panels of decorative half- timbering. The house has two massive chimneys—one projects from the north side of the center mass of the house and the other is a wall chimney on the south façade of the east projection. The chimneys are similar in style and have multiple brickwork flues sitting on rough-cut un-coursed stone bases. The stone rises up beyond the eave of the roofline, and the chimneys are taller than the peak. The home is constructed of un- coursed rough-cut stone, and the roof is covered with the same red tile as the boathouse. The home has a variety of window shapes, but most of the windows are multilight casement windows or multilight leaded windows. A large bay window is to the west of the entrance door. The window is capped with a decorative half-timbered band, and consists of a bank of seven wood-framed, fixed, multilight leaded windows. Other windows on the façade appear to be wood-framed, multilight casement windows. The main entrance is offset to the east on the front hip projection. The entrance is recessed, and a carved wood beam is inlayed above the entryway. The heavy wood door has a lighted panel and multilight leaded sidelights. There is also a non-historic garage, guest house, and gazebo on the island. The house has many of the character-defining features of the Tudor Revival style, including its single dominant gable, half-timbered dormers, asymmetrical plan, tile roof, massive chimneys, front entryway, lattice casement windows, and other architectural features reminiscent of a late-medieval Tudor Revival–style house. Some architectural elements have been altered over time. The 1989 cultural resources inventory noted a number of changes to both the historic landscape and the building. The gazebo and garden house were added in or around 1989, before the inventory, as were stone terraces and paths. The driveway was widened in 2003. Additionally, a stream was constructed that flows through the garden in front of the house (date unknown) and a 3,000-square-foot guesthouse was added to the property after 1987. A 2013 land use file shows that three new structures a cabana, a bridge tower and a tram were proposed for the site. It appears that for the final approval, the tram’s path was altered and the tram car was made smaller, the entertainment area’s size was slightly reduced, and other retaining walls were approved (City of Lake Oswego 2013). On the interior of the home, the dining room and living room remain in original form, while the remaining rooms were reportedly altered or restored after the home suffered water damage. Despite these changes and additions, the exterior’s key character-defining features remain intact.