Halifax is located on Nova Scotia (Canada), a peninsula on the east coast of Canada, which is ideal to monitor the outflow of boreal fires from fires in North America. We present the results of ground-based, as well as space-borne vertically integrated profile measurements of CO and C2H6 in Halifax and in Toronto (ON,Canada); enhancements of those species seen in Halifax and Toronto originated from forest fires in Northwestern Ontario. The column amounts of these trace gases are highly correlated with coincident fine mode Aerosol Optical Depth (AOD) measurements. The emission ratio as well as the emission factor are estimated for C2H6, which suggests that the C2H6 emissions from boreal fires in Northwestern Ontario are higher, than in other geographical regions. We use CMC back-trajectories as well as FLEXPART forward-trajectories to confirm that the origin of the enhanced CO, C2H6 and fine mode AOD seen in Halifax and Toronto between 19 and 21 July 2011 originated from forest fires in Northwestern Ontario. The comparison between GEOS-Chem, using the inventory of the Fire Locating And Monitoring of Burning Emissions (FLAMBE), shows reasonably good agreement with ground-based column measurements of CO, however, differences in the time of the arrival of the plume in Halifax are significant. The modeled C2H6 columns are systematically lower than the observations from ground-based FTIR, which is likely due to the underestimated emission ratio used in the GEOS-Chem simulation.