Complex sentence: Access to the recreation area from the parking lot is up a 4 km trail that this year is being upgraded by the Parks Service and they hope to get the upgrade as far as the middle Joffre Lake.
Split into simpler sentences: Access to the recreation area from the parking lot is up a 4 km trail. Upgrades have been made by the Parks Service in 2017 on this trail, and they hope to continue to upgrade the trail as far as the Middle Joffre Lake.