  An effective-Lagrangian framework for K Sigma photoproduction from the proton
is presented. The proposed model is applicable at forward kaon angles and
photon lab energies from threshold up to 16 GeV. The high-energy part of the
p(gamma,K^+)Sigma^0 and p(gamma,K^0)Sigma^+ amplitudes is expressed in terms of
Regge-trajectory exchange in the t channel. By supplementing this Regge
background with a number of s-channel resonances, the model is extended towards
the resonance region. The resulting ``Regge-plus-resonance'' (RPR) approach has
the advantage that the background contributions involve only a few parameters,
which can be largely constrained by the high-energy data. This work compares
various implementations of the RPR model, and explores which resonance
contributions are required to fit the data presently at hand. It is
demonstrated that, through the inclusion of one K and two K* trajectories, the
RPR framework provides an efficient and unified description of the K^+ Sigma^0
and K^0 Sigma^+ photoproduction channels over an extensive energy range.
