Spring Smelt Run... Mature smelt, 2-3 years of age or older, generally ascend streams to spawn around the time of ice-out (March-May). However, it is well documented that some populations spawn successfully within lakes and ponds that lack suitable spawning tributaries by utilizing shoreline areas or offshore shoals. There is also evidence suggesting smelt may choose to spawn within the lake environment as a result of inclement weather or unfavorable stream flows. The spawning event ranges from 2 days to 3 weeks, but peak activity is usually less than one week in duration. Spawning activity usually occurs at night with most of the spawning individuals dropping back into the lake during daylight hours. Larger individuals of the population spawn first, followed by smaller individuals in the latter part of the run. Spawning fish travel a short distance upstream and position themselves within the current over shallow riffle areas.