5.5 miles, Half day
The trails around Jenkinson Lake can be visited on horseback, mountain bike and foot. This guide, however, is going to focus on hiking.
The full route, if you go all the way around, is just over 8 miles. With the continuous ups and downs it can feel like a lot further though. The total elevation change is insignificant but the small "whoopdedoos" can amount to hundreds and even thousands of feet perceived elevation change. Good physical endurance is a must if you're going to make it all the way.
Getting there: Take the 50 freeway to Sly Park Road (exit #60) and head south for about three miles. The main entrance will appear on the left just across from the Sly Park Resort corner store. You can stop in at the park entrance to check the daily notices but you don't necessarily have to park here. It's at least $10/day to bring a car inside the park from this entrance! There are many spots to park on Mormon Immigrant Trail that cost less and most are actually free. The POIs in this guide will show parking suggestions.
Jenkinson Lake at Sly Park has outdoor activities all times of the year. Snowshoes, cross-country skiing, boating and swimming are enjoyed by many. It's a huge park with more features than most people can visit in one day. There are events in the park that include everything from community mixers to the yearly "Run on the Sly". This park has been voted "Best Recreation Facility by the Mountain Democrat newspaper year after year.
Bring lots of mosquito repellant in the spring and early summer.
First-aid kits and mole skin (for blisters) are a must.
There are a few drinking fountains around the park but you will definitely need to carry a couple extra liters of water.
Mark the location of your car on your GPS
If someone twists an ankle you may need to go get help. Cell phone service is non existent on the north side of the lake. AT&T cellular service works fine on the south side of the lake though. This spotty cell phone access make it a good idea to bring GMRS/FRS radios if you have them. The Garmin Rino series GPS/radio combinations are the best. They allow you to communicate with your group and even send your GPS coordinates to each other. Of course, HAM radios are useful too. Even if you're not a licensed HAM you can still use the 2 meter, 146.805 repeater (negative offset) in the event of emergency. The repeaters in Pollock Pines are used heavily and there's a good chance someone will hear you.
Visit anytime of year. Summers can reach the mid 90's while winters here often have lows in the 20's. Snowfall is very heavy at times and the park does not fully open for camping until mid-may. The entrance gates is often not manned in the winter and this sometimes allows opportunities to drive in through the main entrance for a quick dog walk, trail hike or picnic.