His sister Kelly Johnston said Oroc's family hoped the reward would bring in extra resources to support the ongoing search.
"Experienced hikers and those with ATV or dirt bikes can be of great help as will be any experienced aerial support," she posted on the Go Fund Me page.
Johnston earlier said her brother had survived adventures in the past that had come down to the wire, and if anyone could survive the situation it was him.
"His friends and family know, if anyone could walk out of this situation with a tall tale to tell it is him."
She asked people to contribute to the Go Fund Me campaign to help fund the search, which is on rugged and difficult terrain.
"We are grateful for each and every donation, but need to keep the funding coming too so the intensive search can continue looking for our brother."
More than $137,000 has now been raised in donations to support the search.
Oroc was reported missing in Nevada on Saturday, local time, following 24 hours of no contact with the two other pilots he was flying with.
He lifted off from the Shoshone Mountain, near Round Mountain in Nevada and planned to fly to Wendover, a Nye County Sheriff's Office (NCSO) spokesman said.
Oroc's GPS tracker showed he was last recorded at about 14,500ft in the Ninemile Peak area at 2.14pm on Saturday.
By then, Oroc had been flying for around three hours and had covered 86km.
He'd planned to cover another 114km before the end of the day.
"Ninemile Peak area has an altitude ranging from 8800 feet to 10,000 consisting of rugged forest terrain," the NCSO spokesman said.
A journalist, photographer and artist, Oroc regularly flew long distances: in November 2018 he broke his previous New Zealand overseas open distance record by flying 384km in Quixada, North Brazil.
He also held the previous record - 316km.
