The Grotto was established in 1924 by Friar Ambrose Mayer, a native of Ontario, Canada, who was sent to the United States where he was a Servite pastor for the Archdiosese of Portland, Oregon. Upon moving to Portland, Mayer found acreage located outside Northeast Portland that was at the time owned by the Union Pacific Railroad Company, and had been put up for sale to be developed into residential property. Mayer made a downpayment of $3,000 and purchased the property in 1923.A national campaign raised the balance of the funds needed to pay for the land.