At this point, it's no secret that the current interest rate environment is terrible for savers. As the Federal Reserve has kept short-term rates low in order to spur the economy, many traditional income sources have come up dry. Money market funds, CDs and short-term bond funds such as the Guggenheim Enhanced Short Duration Bond ETF (ARCA:GSY), all now pay next to nothing. To that end, investors wanting to live off their savings have been forced to look at some non-traditional choices. Master Limited Partnerships (MLPs) have exploded in popularity over the last few years, given their high yields. The bulk of investors' focus, however, has been strictly on the midstream pipeline firms. For those willing to expand their horizons, there is a whole world of other high yielding MLPs to choose from.

Forex Broker Guide: Using the right broker is essential when competing in today's forex marketplace.

Income at the Wellhead
While most investors are familiar with traditional energy exploration and production firms such as Range Resources (NYSE:RRC), some have decided to take a different path in going public. Structured as master limited partnerships, these "upstream" MLPs feature many of the same benefits as their pipeline twins - high dividends and tax breaks - while providing a direct way to play the long-term growth in energy pricing.
Upstream MLPs generally build, operate and maintain wells for various energy resources and, like their E&P twins, thrive on generally higher oil and natural prices. Unlike their C-corp. structured rivals, however, their tax structure requires them to pay out the bulk of their earnings back to unit holders and doesn't allow for a "rainy day fund." This requires upstream MLPs to focus on developed acreage with mature production profiles. The average upstream MLP well vintage exceeds five years and has limited drilling risks.

Believe it or not, there's plenty of growth to be had in active mature wells. For large energy producers, it's generally not economical to hold onto mature wells for too long - especially when then there are high-growth shale opportunities available. To that end, many big E&P operators will sell off their mature assets to upstream MLPs - at a huge discount - in order to focus their efforts on these newer deposits. According to a May 2012 report by boutique investment bank MLV, "The wave of exploration and shedding of mature assets by producers could result in a 10-fold increase in MLP-appropriate assets." All in all, those asset sales will boost the upstream MLPs resource bases and provide a steady stream of dividends to unit holders.

Adding some Upstream Oomph
While most broad MLP funds such as the JPMorgan Alerian MLP Index ETN (ARCA:AMJ) do include some exposure to the upstream MLP players, the bulk of their holdings are in the pipeline and midstream providers. To that end, investors wanting to add the sector need to go the individual route.

Perhaps the best upstream MLP can be found in Linn Energy (Nasdaq:LINE). Since going public in 2006, the firm has managed to grow its reserves to more than 5.1 trillion cubic feet of natural gas equivalent. More than 45% of that is in more richly-priced oil and natural gas liquids. The company thrives on its low costs and steady production profiles and continues to add to its resource base. Linn recently purchased BP's (NYSE:BP) Jonah field for $1 billion. That will add 750 producing wells to its arsenal. Linn currently yields a juicy 7%. Investors interested in Linn may also want to take a look at its recent IPO LinnCo (NYSE:LNCO) as well. That firm will hold roughly 13.2% of Linn Energy.

Offering a higher yield at 9.2%, BreitBurn Energy Partners (NASDAQ:BBEP) could be a great income bet. After canceling its distributions a few years ago during the economic crisis, the firm has bounced back and continues to trade at a discount versus its upstream peers such as Vanguard Natural Resources (NYSE:VNR). New acquisitions in the Eagle Ford shale will help continue the payouts coming.

SEE: 5 Biggest Risks Faced By Oil And Gas Companies

The Bottom Line
With interest rates at historic lows, most investors have flocked to pipeline MLPs to get their yield fix. However, they aren't the only MLP game in town. The upstream MLPs offer a chance to participate in steady mature fields and gain some income at the well head. The previous picks, along with Mid-Con Energy Partners (Nasdaq:MCEP) make ideal choices to play the sector.

At the time of writing, Aaron Levitt did not own any shares in any company mentioned in this article.

Want to learn how to invest?

Get a free 10 week email series that will teach you how to start investing.

Delivered twice a week, straight to your inbox.