Properties of the hadronic final state in photoproduction events with
large transverse energy are studied at the electron-proton collider HE
RA. Distributions of the transverse energy, jets and underlying event
energy are compared to <(p)over bar p> data and QCD calculations. The
comparisons show that the gamma p events can be consistently described
by QCD models including - in addition to the primary hard scattering
process - interactions between the two beam remnants. The differential
jet cross sections d sigma/dE(T)(jet) and d sigma/d eta(jet) are meas
ured.