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precipitation in high-elevation areas Occurs as snow from December to April and, beginning in October, a deep snowpack accumulates. Snowmelt begins in late April and continues well into June or early July. Snowfall in Craig is not extremely heavy, with annual totals ranging from 33 to 77 inches. Rain may occur over the area, and convective-type cloudburst storms frequently occur in summer. Development in the flood plain of Fortification Creek consists primarily of single-family housing. Development in the flood plain of Brothern Gulch is predominantly mobile home parks. Very little land in either flood plain is undeveloped. The flood plains of Tributaries 1 and 2 are primarily undeveloped along the upper one-half and have low-density housing and trailer parks along the lower one-half. 2.3 Principal Flood Problems Major flooding in the Craig area has been the result of rapidly melting snow, sometimes augmented by rain, during the period from March through June, or precipitated by ice jams in late winter or early spring. Snowmelt flooding is characterized by moderate peak flows, large volume of runoff, long duration, and marked diurnal fluctuation of flow. Major flooding from rain alone is not known to have occurred in the Craig area, but there is no reason to conclude that very large floods resulting from rain are not possible in the Yampa River basin. Flooding from rain is characterized by high peak flows and moderate duration of flood- flows. Flooding from convective-type cloudburst storms is charac- terized by high peak flows, short duration of flow, and small volume of runoff. Because cloudburst storms are small in areal extent and short in duration, they constitute a flood threat on streams as small as Brotherton Gulch and Tributaries 1 and 2. Ice jams have constituted a signficant debris problem, particularly along Fortification Creek, where historically ice jams at highway and railroad bridges have caused substantial flood damage. However, channel improvement work, largely accomplished on a emergency basis in 1949, and improvement of the bridges appear to have reduced the occurrence of ice jams at these locations. Ice in Yarnpa River and the anabranch channel that carries Fortification Creek flow to the main stem can also create flood conditions in Craig. A special significance of ice jams is that the locations of their occurrence and their impact are indeterminate. Not only is it impossible to predict where an ice jam will occur, but the area that could be affected by overflow and the resultant depth of flooding are also elusive. Flow that would otherwise be non-damaging could, if associated with an ice jam, flood areas ordinarily consid- ered flood free. 6