Construction begins this week on a new trail to replace an aging one at Sheep Gulch Boat Ramp in the Snake River Canyon four miles north of Alpine. According to Bridger Teton National Park officials, the trail going from the Sheep Gulch Ramp area to the upper parking area will be closed until May 18thwhile construction of a new trail above is under way. That is because rock or other material could roll down on persons on the old trail. The work making the cuts for the new trail should be finished within a week allowing the old trail to be reopened while less dangerous finishing work continues above. Forest officials made the decision last fall to replace the aging trail used by approximately 120,000 persons annually as they depart the cramped boat ramp area, to waiting outfitter buses, or parking areas 400 feet above.