Official Medal of the 1905 Lewis & Clark Exposition in Portland, Oregon. Shevlin SH 14-1, Swoger 16d (presumed). This appears to be the Brass version based upon planchet color. I have seen enough being located less than 100 miles from the event to be sure that this is not the Gold-plated Bronze version, nor do the surfaces appear to be what I would call "Bronze". As Jeff Shevlin points out, specific determination is difficult depending upon surface toning, absent x-ray spectrographic analysis. I would guess that planchet sourcing was not the foremost thing on the minds of the promotors of the event, and so considerable variability could logically be expected. Otherwise this is a problem free Almost Uncirculated specimen, showing some light wear on the high points of the design from brief pocket carry. Light toning from many years spent stored in a leather purse, no spots or damage.