The distance to the Chain A high-velocity cloud complex

We present high-resolution (R similar to 5 km s(-1))Na I and Ca II interstellar absorption line spectra observed toward five B stars in the line of sight to the high-velocity cloud complex Chain A. We have failed to detect the presence of any high-velocity (V < -100 km s(-1)) interstellar absorption toward these stars. This null detection enables us to place a new lower limit on the distance to the Chain A complex of z greater than or equal to 837 +/- 200 pc, assuming normal gas-phase abundances of Na I and Ca II. If this distance determination is typical for other high-velocity clouds, it poses problems for theories that currently argue these clouds interact with the galactic disk.