Transport aircraft. It’s a four engine turboprop that can take off and land from dirt airstrips as well as a paved runway. Can carry cargo or troops. It’s used for parachute jumps too.

That particular variant (non special ops) is a cargo and/or personnel transport. Another thing that caught my attention with this J-model is that it is flying considerably below it's top speed. Very heavy, maybe?

Some trivia:

General characteristics

Crew: 3 (two pilots, and one loadmaster are minimum crew) Capacity: 92 passengers or 64 airborne troops or 6 pallets or 74 litter patients with 5 medical personnel 2–3 Humvees, or 1 LAV III (with turret removed) or an M113 armored personnel carrier Cargo bay length: 41 ft (12.50 m) Cargo bay width: 10 ft (3.05 m) Cargo bay height: 9 ft (2.74 m) Payload main: 42,000 lb (19,051 kg) Length: 97 ft 9 in (29.79 m) Wingspan: 132 ft 7 in (40.41 m) Height: 38 ft 10 in (11.84 m) Wing area: 1,745 sq ft (162.1 m2) Airfoil: root: NACA 64A318; tip: NACA 64A412[136] Empty weight: 75,562 lb (34,274 kg) Max takeoff weight: 155,000 lb (70,307 kg) Powerplant: 4 × Rolls-Royce AE 2100D3 turboprop engines, 4,637 shp (3,458 kW) each Propellers: 6-bladed Dowty R391 composite constant-speed fully-feathering reversible-pitch propellers Performance

Maximum speed: 362 kn (417 mph, 670 km/h) Cruise speed: 348 kn (400 mph, 644 km/h) Range: 1,800 nmi (2,100 mi, 3,300 km) at max normal payload (34,000 lb (15,422 kg)) Service ceiling: 28,000 ft (8,500 m) with 42,000 lb (19,051 kg) payload Absolute ceiling: 40,386 ft (12,310 m)

Looks like maybe Ft. Riley