As water moves carbon through watersheds and across ecosystem boundaries, stream corridors collect and integrate landscape-scale signals of carbon cycling. Streams metabolize organic carbon and emit carbon dioxide (CO 2 ) and methane (CH 4 ) derived from internal metabolism and external sources (Hotchkiss et al., 2015;Stanley et al., 2016). The rates at which streams emit carbon to the atmosphere reflects their importance in local and global carbon cycling. Streams emit CO 2 globally at a rate that surpasses the terrestrial and oceanic carbon sinks (Webb et al., 2018) and emit approximately 5% of yearly global CH 4 to the atmosphere (Flury & Ulseth, 2019;Stanley et al., 2016). As global concentrations of atmospheric greenhouse gases continue to rise, quantifying the relative contributions of different sources and sinks of CO 2 and CH 4 grows ever more important.