Abstract The objective of this field trip is to examine variability in stream systems in west-central Ohio at different time and space scales. Scales of study range from watershed changes over 10 3 –10 4 years as drainage networks are established during glacial retreat, to reach-scale changes in tributary streams in response to human impacts and land use change over 10 1 –10 2 years, to diurnal and event-driven changes in water quality over 10 –2 to 10 –3 years. Drainage network changes in the Little Miami River and Mad River systems occurred through stream capture and were dependent on the location of early meltwater channels relative to ice lobe position and relict bedrock topography. At the reach scale, channel morphology (width, depth, slope, shape, and pattern) is dependent on mean discharge of water and sediment to the reach. Tributary streams to the Little Miami River, Mad River, and Buck Creek illustrate the impact that historic changes in land use, water and sediment discharge, channelization, and straightening of stream reaches have had on channel morphology and vertical stability. At the cross-section scale, flow characteristics, including stream stage and physical water quality parameters (temperature, pH, specific conductivity, oxidation-reduction potential, dissolved oxygen, and turbidity), are being measured on Buck Creek and Beaver Creek. Though some characteristics change diurnally in response to internal stream processes, event-based changes in response to stormflow reflect source area contributions of runoff and sediment.