The poster says it all: "Clean Up Illegal Dump."

The "Illegal Dump" is Walking Purchase Park.

The 530-acre "urban wilderness" is tucked between the northern slope of Lehigh Mountain and the banks of the Lehigh River in eastern Salisbury Township.

The Lehigh Mountain Park Master Plan for the park was prepared in 2008 and revised in 2009 and 2010.

Salisbury, along with Lehigh County and Allentown, the three government organizations jointly administering Walking Purchase Park, have big plans for the densely wooded area, including a boat launch someday.

The operative word is "someday."

For now, it is cleanup day, 8 a.m. to 4 p.m. April 26, at Walking Purchase Park.

Volunteers are needed.

Those interested in helping with the cleanup are to park their vehicles on the upper parking lot of Fearless Fire Company, 1221 S. Front St., Allentown. From there, volunteers will be transported to the park via the western entrance, at Constitution Drive. The eastern entrance is Riverside Drive, accessible off South Third Street, Bethlehem.

The cleanup is being coordinated by the Salisbury Township Environmental Advisory Council as its Earth Day activity for this year.

It's not the first time volunteers have cleaned up the park. Despite the installation of police surveillance cameras, those attending the township EAC's April 15 meeting were told more trash than ever has been dumped in the park.

The dumping is happening despite the presence of members of the Valley Mountain Bikers, who have constructed a network of some 10-plus miles of multi-use trails in the park.

At the township EAC meeting, it was stated sites along Constitution Drive have been tagged where litter is located.

"Most of the debris has worked its way to the base of the mountain," according to the EAC agenda.

"There is a tremendous amount of electronics such as televisions that have been dumped," it was stated.

Dumpsters will be in the park for placement of some of the debris.

Those interested in helping with the cleanup are to contact Karen El-Chaar, STEAC member, at kelchaar@allentownparks.org or 610-432-7275, or Cynthia Sopka, Salisbury Township director of planning and zoning, at csopka@salisburytownshippa.org or 610-797-4000.