Below is summary of the regulations for Wisconsin’s Tributaries. For the complete current regulations see the DNR’s Hook & Line Regulations (not the inland trout regs.)

Lake Michigan Tributaries are open from the river mouth up to the first dam or migratory blockade. The season is open year around except for Lake Trout.
Daily bag limit: 5 trout and salmon in total, only 2 may be lake trout
Size limit: 10"
Hours: From October 1 to May 7, hook and line fishing is prohibited from one-half hour after sunset to one-half hour before sunrise in all tributaries except the Peshtigo River upstream to the first railroad bridge and the Oconto River and its tributaries.  See regulations for current details

Lake Superior Tributaries: the season runs from the first Saturday in May until September 30. The bag limit is 5 trout and salmon in total, only 2 of which can be Browns over 15" and only one Rainbow (Steelhead). Size limits are 8" for Brook Trout, 10" for Brown Trout, 12" for Salmon, and 26" for Rainbow Trout-a real trophy! You do not need a Great Lakes Stamp for Lake Superior but you do need an Inland Trout Stamp.