Much of Riverview is the result of sand and gravel operations. Our hill used to be a little higher than it is, in some places. Beyond harvesting the sand and gravel, the plans were to level off land that could have neighborhoods built on it.
The Whitlock Woods property had been owned by Klinker Sand and Gravel. The Department of Engineering bought some of the property outright and then traded their own sand and gravel operations, located where South Seattle Community College is now, for the remainder.
The DOE then built a service road from the base of Highland Park Way up to 14th Ave SW and SW Holly St, with a specified 10% grade up to 14th & Morgan. This allowed the city to use this property as a Sand and Gravel pit to provide fill for the 1st Ave South bridge construction. Most of this road remains intact today, though other areas have become overgrown. The trucks would come up the hill to be filled, then continue up and exit at 14th & Holly before looping back down Highland Park Way to dump their loads.
I believe the above was shot around 1966. This image was provided to me by SSC during our effort to save the Soundway property. The street running through the right side of the photo is 16th Ave SW. The intersection at the bottom is 16th Ave SW and SW Brandon Street. SW Brandon Street does not extend as far East now and SSCC begins South of it. Just South of the swirling roads (near the top) you can see a large flat area that is now Riverview Playfield. The street in front of it is 12th Ave SW. It runs South to SW Holly St. SW Holly Street does not yet appear to connect to 14th Ave SW.
Below is a picture from 1966. Note that the progress on the Riverview Playfield seems to be about the same as on the previous image, which is why I believe the previous image is from the same time frame.
Below is an earlier picture of the Boeing plant. It also captures the original 1st Ave South Bridge. Be sure to click on the image to see the full size. You can clearly see the sand and gravel operations up the hill, which are now Riverview Playfield and South Seattle College. Interestingly, there is also a clear sidewalk on the right-hand side of Highland Park Way that has been buried/overgrown for years.