Test crosses, constructed from twelve different softwoods and nine different hardwoods, were exposed on test fences for 9-12 years in both southern Mississippi and Wisconsin. The woods tested in Mississippi were classified into aboveground decay resistance groups. The sapwood of lodgepole pine, basswood, balsam poplar (<i>Populus balsamifera</i>), red alder (<i>Alnus rubra</i>), and sweetgum and the heartwood of sugar maple, yellow birch (<i>betula alleghaniensis</i>), and basswood decayed within an av. of 7 years and were classified as nonresistant. Woods estimated to last over 20 years above ground, and thus classified as most resistant, included heartwood of Douglas-fir, redwood (<i>Sequoia sempervirens</i>), western white pine (<i>Pinus monitcola</i>), red and white oak, and sapwood of red oak. The remaining woods fell in between these classes. In Wisconsin most woods decayed too slowly for estimates to be made of their longevity. The predominant fungi in the Mississippi test site were: <i>Gloeophyllum saepiarium</i>, the white-rot fungus Unknown T, <i>Schizophyllum commune</i>, the brown-rot fungus Unknown U, and a <i>Xylaria</i> sp. In Wisconsin, <i>Peniophora cinerea</i>, <i>Phanerochaete chrysosporium</i>, <i>Meruliopsis corium</i>, $2<i>rpex lacteus$$, and <i>Peniophora violaceo-livida</i> predominated. -- AATA