A tree structure and method to organize routing information for processing messages within a network, each message being associated with a search key of "n" bits. The processing determines where to send the message next. The structure has a direct table (DT) of 2^x entries for decoding the first "x" bits of the search key, and one or more pattern search control blocks (PSCB's), each having 2^m entries for decoding subsequent groups of "m" bits. Each PSCB entry and DT entry includes a pointer to data associated with a specific route, if at this point a specific routing table entry is a potential match to the search key or a pointer to a subsequent PSCB if the end of a search trail is not identified. Each PSCB entry DT entry also indicates that the search has been resolved to the end of the search trail.