According to NFL Network's Jane Slater, the deal would have paid the quarterback $70 million over its first two years and averaged $33-35 million per year with $110 million guaranteed. The two sides were unable to finalize an agreement before the NFL's 4:00 p.m. EST deadline.
Prescott will instead play the 2020 season on the franchise tag.
An average annual salary of $35 million would've tied Prescott with Seattle Seahawks quarterback Russell Wilson for the second-highest AAV in the league.
Kansas City Chiefs quarterback Patrick Mahomes now holds the top spot with an AAV of $45 million.
A $110 million guarantee alone would've made Prescott the 14th-highest-paid player in the league and a $50 million signing bonus would've tied for third-most in the NFL with Detroit Lions quarterback Matthew Stafford.
Instead, Prescott will earn a total of $31.4 million this year playing on the franchise tag.
The fourth-round draft pick out of Mississippi State in 2016 had previously said he wants to be a Cowboy for life, but Wednesday's development—along with previous statements by the franchise that a long-term deal was imminent—could severely complicate that.
Prescott will become an unrestricted free agent following the 2020 season, with Spotrac.com projecting his market value at $38.5 million per year, or worthy of a five-year, $192.6 million contract.
That would make him the second-highest paid player in the league behind Mahomes and with a relatively weak free-agent class, there may be more incentive for teams to up their bidding.
What's clear from Slater's reporting on Wednesday, however, is Prescott's willingness to strike a deal even as it seemed almost impossible to do so.
It doesn't bode well for Dallas fans that the club was unable to match his desire.
For his part, Prescott told Slater he feels "grateful and blessed" to be a Cowboy today and is continuing to work towards winning a Super Bowl with the team.
Reported contract details via Spotrac.com