De Los Santos carded a 77 Monday at the Riviera Country Club and a 72 Tuesday at Bel Air for a nine-over-par 149 total, tied for 135th place. De Los Santos posted two birdies, five bogeys and a pair of double bogeys in the first round and rebounded with three birdies and five bogeys Tuesday.
Engelhardt recorded a 77 on Monday at Bel Air and a 78 Tuesday at Riviera for a 155 total and 250th place among the 312 golfers in the field. Engelhardt notched two birdies, seven bogeys and a double bogey Monday and one birdie and nine bogeys Tuesday.
The cut was at 144, with 64 qualifiers advancing to Wednesday's first round of match play.
Hayden Wood followed up a 64 on Monday with a round of 67 on Tuesday at Bel Air, setting a U.S. Amateur 36-hole scoring record with his 131 total.
At the 117th U.S. Women's Amateur held August 7-13 at the San Diego Country Club in Chula Vista, Cal Poly's Jamie Binns missed the cut for match play by one stroke.
Binns posted a 76 and 75 for a seven-over-par 151 total. The cut was at 150.
Binns carded four bogeys and 14 pars in the opening round and four birdies, five bogeys and a double bogey in the second round.
Delisa Schubert, a University of Texas senior, defeated Stanford University standout Albane Valenzuela, 19, of Switzerland, 6 and 5, in the 36-hole championship match on the 6,423-yard, par-72 layout.