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dry for 33 years. The 48 month graph (Figure 7e) shows the clearest view ofIonger time-scale precipitation. The bottom with SPI < -I shows the two long periods 1905-1931 and 1979-1996 were wet with only small drought occurrence. Colorado is clearly now in an extended period with less drousht impacts. The top of Figure 7e indicates the current wet period is similar to the one beginning in 1905 but the 1983-1988 period had a larger fraction of stations above 0.4 for a longer time period than the earlier wet period. The depiction of dry and wet periods in Table 4 provides a broad overview of drought periods in Colorado that have affected large areas of the state. Wet periods tend to last longer than dry periods and no extended dry periods have occurred since the 1950s. The beginning period of 1893-1905 was dry but the number of observing sites was smaller and changing. A rather long wet period followed from 1905-1931 with brief moderately dry periods in the early teens and again in the early to mid 1920s. The 1950s and 1960s had shorter periods of dry and wet conditions with 1951-1957 dry, 1957-1959 wet, and 1963-1965 dry again. A longer period for 1965-1975 was wetter but not to the extent and duration of earlier periods. A brief dry period followed in 1975-1978 and then a change occurred to start the wet period from 1979 to 1996 with one lull in the late 1980s to early 1990s. From the state as a whole the next view of dry or wet periods is seen on a regional level within the state. The SPI for each region is shown in Figure 8 and the SPI in each graph is the average of the SPls of all stations in the region. This was done so that wetter or drier locations would not dominate the combined indicator for the region. All of the periods in which SPI is greater than 1 or less than -1 are shaded to clearly indicate when drought or wet conditions were present in the region. In these graphs the averaged SPls are not uniquely connected to probability 17