Upper Den wasn't exactly their ideal buyer. The intent was clear that much of the landscape's natural features would be razed over to make way for entertainment infrastructure. However, Upper Den had the most generous offer and no competition, so the Board was forced to accept.

Construction efforts started in 2777, weaving a track through some of Mt. Nabethea's surrounding glaciers and into the Bethean cave system. Using existing access routes from the E.S.B, and with Upper Den's extensive resources, the track - now named Bethea Speedway - was completed in just over a year.

At first, the venue only opened for occasional public track days for those with MPT vehicles, but mostly served a playground for Upper Den's leadership. This quickly changed, as manufacturers began to reserve private sessions, chasing lap records for various civilian MPT-ship classes. Interest snowballed, with more enthusiasts coming on track days, alongside the growing rivalry between multiple manufacturers frequently trying to outclass one another.

With lots to gain from the surge of interest, Upper Den pitched an endurance event; the 25 Hours of Bethea. No MPT vehicle was officially rated for a 25 hour runtime, but the concept piqued the interest of enthusiasts, pro-level racing pilots, and even a few manufacturers. The event was later officialized in 2779, using the existing layout.

The first run of the 25H of Bethea was a success, and over the course of a few years, it established itself as a pinnacle racing event for racing-sport pilots and manufacturers. Some manufacturers even relocated or opened new branches in Adept, finding Bethea Speedway to be an ideal testing ground.

Word began spreading in 2783 that the RSEC were scouting Bethea Speedway as a possible addition to the HSRL calendar.

However, in 2784, a glacier fragment had broken off, falling just on the edge of the circuit. Drawing much concern for the safety of the track (but mainly its potential viability for the HSRL), Upper Den shut the venue down sought a fast, reliable way to make it safer. The search led them back to the E.S.B, with Upper Den asking to periodically assess the venue and the surrounding region, with advisory for safety/structural implementations. The Board's asking price was steep, but with an HSRL slot potentially on the line, Upper Den agreed, starting a long-time partnership between the two.

The deal seemed to be the right call as a few months later, the RSEC had begun talks with Upper Den; and by 2785, Bethea Speedway was on the HSRL calendar as the Nabethea Grand Prix. This would be Erios' second track on the calendar, introduced a few years after Exaria Bay, located at the edge of Adept's Zone 2.

The circuit was deemed a total loss; both the Board and Upper Den had absorbed severe losses.

Two years would pass, and Upper Den were essentially sitting on a dud with Bethea. Realistically, their best course of action would be to sell off the area and move onto other ventures. But doing so would have severed the funding that had finally let the E.S.B. properly maintain Erios' other conservation sites. In response, the Board pushed Upper Den to rebuild, going so far as to contribute a significant share of its own workforce and equipment under contract. 

After multiple meetings, Upper Den agreed to rebuild Bethea.