  PKS 1424+240 is a BL-Lac blazar with unknown redshift detected at high-energy
gamma rays by Fermi-LAT with a hard spectrum. It was first detected at
very-high-energy by VERITAS and latter confirmed by MAGIC. Attempts to find
limits on its redshift include three estimations by modeling gamma-ray
observations, and one obtained by analyzing Lyb and Lyg absorption lines
observed in the far-UV spectra (from HST/COS) caused by absorbing gas along the
line of sight. They allowed to constrain the redshift range to 0:6<z<1:19,
which places PKS 1424+240 in the very interesting condition to be one of the
few candidates to be the most distant blazars detected at very-high-energy
gamma rays. Redshift determination of BL-Lac objects are difficult to achieve.
We have found that redshift of blazars can be determined by its association to
a galaxy group or cluster. To explore this possibility for PKS 1424+240, we
have carried out spectroscopic measurements with the Gemini North telescope of
galaxies in its field of view. In this work we present the optical spectrum of
PKS 1424+240 and show preliminary results of the blazar environment
characterization. Spectroscopic redshift using the optical spectrum of PKS
1424+240 could not be determined in this work.
