[6]: 18–19  Secretary John A. Volpe officially designated the site in January 1970;[7] a 50-year lease was signed by the DOT and the State of Colorado on August 22, 1970.

[6]: 19  The state land board acquired several small parcels to assemble a contiguous site, and under the terms of the lease, the cost was $10 and had two renewal options.

[6]: 21–23  In addition, preliminary design work continued for the Suspended Vehicle System (SVS) and the Tube Vehicle System (TVS); SVS was designed to take advantage of existing rights-of-way and be capable of greater roll angles (and higher speeds), and TVS was expected to operate in all weather conditions at speeds up to 500 mph (800 km/h).

[5]: 4, 11  Although the FRA retained overall management of the facility, other government agencies were encouraged to participate, and the Urban Mass Transportation Administration (UMTA) constructed the Rapid Transit Test Track (TTT) onsite to test transit cars;[5]: 11  the initial 2.4 mi (3.9 km) segment of a planned 9.1 mi (14.6 km) oval was started in March 1971 and completed in August by Morrison-Knudsen.

[13]: 6 The TTT was dedicated on October 12, 1972, during a ceremony that also included the unveiling of the State-of-the-Art Car (SOAC); the principal speaker was Secretary Volpe.

[8]: 87 Temporary site headquarters and personnel offices initially were set up in five trailers to support early testing; the Program Management Building (PMB) was the first permanent structure to be completed, housing administrative personnel, designed by Bertrum Bruton Associates (of Denver);[5]: 13–15  the PMB was completed and occupied in February 1972.

[8]: 89 The LIMRV set a world record for rail vehicle speed at HSGTC on August 14, 1974, 255.4 mph (411.0 km/h).

The site had cost $55 million to construct to-date, and plans were advancing to continue research on hovertrains.

[8]: 42  The UTACV program selected Rohr to build a Prototype Tracked Air Cushion Vehicle (PTACV), and construction of an inverted-T guideway began in May 1973.

[15] A contract was let in 1972 to begin grading the route for the Railroad Test Track (RTT), a planned 14 mi (23 km) high-speed loop operating conventional rail vehicles up to 160 mph (260 km/h); within the high-speed loop, a Dynamics Track sub-loop 9.9 mi (15.9 km) long would investigate passenger and freight train dynamics at slower speeds.

[16]: 7  Trains operated at relatively low speeds up to 35 mph (56 km/h) for 16 hours a day; one early conclusion was that steel railroad ties were impractical, as they began to crack after bearing 26 million gross tons of freight.

[8]: 93  Due to reduced funding that threatened to close the facility, the FRA entered a public-private partnership with AAR in October 1982, who would take over "care, custody, and control" of TTC.

[21][22] In March 2021, the FRA awarded the "care, custody, and control" contract to ENSCO, who assumed responsibility for operations and maintenance of TTC in October 2022.