The cache is a Terrain: 
if you come from above.
The cache is a Terrain: 
if you come from below.
You are looking for a small camouflaged Lock & Lock container.
Update 11/06/2011: I was able to confirm that there is a letterbox in the vicinity. This letterbox had been mentioned in logs of the wkellogg01 hide that used to be close to this location. The letterbox, which is a clear plastic container with a blue ring on top, is over 60 feet from this cache. If you have found the blue ringed container, it is not the cache. Letterbox Listing: Jake's Third Birthday
Alpine Park
Alpine Park is a 78.18 acre park that has been around since the 1940's or 1950's. In those times, Alpine Road was a two-lane country road quite removed from Rockford proper.
Next to the entrance of the park, there now stands a small maintenance building that may have existed at the time of dedication of the park. Around that building there previously existed a small grassy area that could be used for recreational activities without going further back into the Park. With the expansion of Alpine Road from a small two lane road to a four lane city street, this small area was lost. This small area can be seen in the photo below. The rock cliff also seen in the photo can still be seen today as you fly by on Alpine Road.
Today, the center of the city has moved to this area with the expansion towards I-90 to the East. The park has some small sheltered areas with picnic tables, picnic areas, bathroom facilities, playground with swings, sandbox, and plenty of open spaces to discover nature. This park can be an unexpected green area in an urban jungle to some, but to the Forest City it is a vital area. The popularity of the park is still fairly high but its facilities are not as plentiful as some of the other parks. Alpine Park Pool, also maintained by Rockford Park District, is in a small extension of land to the South of the main park behind the Colonial Village Shopping Center.
Statistics:
Address: 950 S. Alpine Rd.
Additional facilities: Swimming Pool, Accessible Playground
Acreage: 78.18
Shelters: 2
Picnic Areas: 8
Playgrounds: 1 (handicap accessible)