Complex sentence: Highway 63 serves as the main road through Fort McMurray where it crosses the Athabasca River before connecting the city to the Syncrude and Suncor Energy plants further north before ending approximately beyond its second crossing of the Athabasca River northeast of Fort MacKay.
Split into simpler sentences: Highway 63 serves as the main road through Fort McMurray where it crosses the Athabasca River before connecting the city to the Syncrude and Suncor Energy plants further north. It ends approximately beyond its second crossing of the Athabasca River northeast of Fort MacKay.