When there were far fewer people around, far fewer laws and regulations, when the legal speed limit was 75 mph, when gas was cheap, when driving was a pleasure, if you owned a hot machine you could point the grill down an empty road and go!

Exploring (Excerpt from "One Summer")

A photo from the Oregonian of the front of the second Lents Public School, 1910 - 1950.
The following is excerpted from the novel One Summer by Albert Drake. Drawing from personal experience, as well as historical events of Portland, Drake weaves the story of a teen in the summer of 1948 that is simultaneously nostalgic and honest. In the chapter "Exploring," the boys visit an abandoned school.
They stood within the cool shadow of the alcove at the rear of the school; on one side was the grassless playground, where huge dusty-brown grasshoppers clacked with urgency in the hot sun, and on the other side the black maw of the open door.
After circling the empty school building, testing every door, they had found this one open. “C’mon,” Horace said again, peering up the darkened stairway as if it were the abandoned fort in Beau Geste. 
Chris looked around the serrated cement column and listened— the empty streets, the dusty playground, grasshoppers—and then he turned and entered the school.
The stairwell was dark and they waited until the familiar objects materialized: the oak bannister, the narrow tongue-and-groove panelling, the foot-worn steps. The school had been in use for over fifty years, and soon it would be demolished.
The slightest noise echoed against the wooden walls, and Chris was sure he could hear the echo of his pounding heart. The halls smelled of sawdust and linseed oil; how many times had he seen Johnny Johnson (“Yonny Yonson”), the janitor, spread against the oak boards to clean up a kid’s vomit? They stood in the darkness of the main hall, dark at two on a brilliant summer day, and darker than anyone could imagine on a rainy winter day.
Inside, the school was both scary and comfortable. He remembered how after one had arrived at the school one was held in the warm classrooms and protected against wind and rain. Many days he had felt the school was cozy; the poor old cafeteria always spouted forth the delicious odor of hot, homemade tomato soup; the poor old auditorium with its folding wooden chairs brought them together for songs and Christmas plays and sometimes a flickering movie showing Sinbad or Gulliver. 
They wandered downstairs and into the gym, whose cement floor had the chill of winter. How many teeth had been chipped or broken on that cement? he wondered, probing with his tongue his own partially missing front tooth. They cautiously pushed open the door to the boys’ john, with its strange labyrinth of tall water reservoirs and pipes. Here Bobby Meersham had fallen while jumping from pipe to pipe and had fractured his skull; perhaps, Chris thought, that accident was what had made him a little nutty.
The inspiration for this story is second Lents School in Portland, Oregon, pictured below.

As others have written...
"The first Lents School at 92nd and Harold in Portland - a wooden structure built in 1902 after a previous school at another location had burned. Note the rural character of its surroundings. It only served for eight years, as in 1910 is was replaced by a new, larger brick and stone structure, also at 92nd an Harold. The newer building lasted until 1950, when it in turn was replaced by the current school at 97th and Steele."

You can purchase copies of One Summer here.